Background:Under hypoxia,exaggerated compensatory responses may lead to acute mountain sickness.The excessive vasodilatory effect of nitric oxide(NO)can lower the hypoxic pulmonary vasoconstriction(HPV)and peripheral ...Background:Under hypoxia,exaggerated compensatory responses may lead to acute mountain sickness.The excessive vasodilatory effect of nitric oxide(NO)can lower the hypoxic pulmonary vasoconstriction(HPV)and peripheral blood pressure.While NO is catalyzed by various nitric oxide synthase(NOS)isoforms,the regulatory roles of these types in the hemodynamics of pulmonary and systemic circulation in living hypoxic animals remain unclear.Therefore,this study aims to investigate the regu-latory effects of different NOS isoforms on pulmonary and systemic circulation in hypoxic rats by employing selective NOS inhibitors and continuously monitoring hemodynamic parameters of both pulmonary and systemic circulation.Methods:Forty healthy male Sprague–Dawley(SD)rats were randomly divided into four groups:Control group(NG-nitro-D-arginine methyl ester,D-NAME),L-NAME group(non-selective NOS inhibitor,NG-nitro-L-arginine methyl ester),AG group(in-ducible NOS inhibitor group,aminoguanidine),and 7-NI group(neurological NOS in-hibitor,7-nitroindazole).Hemodynamic parameters of rats were monitored for 10 min after inhibitor administration and 5 min after induction of hypoxia[15%O2,2200 m a.sl.,582 mmHg(76.5 kPa),Xining,China]using the real-time dynamic monitoring model for pulmonary and systemic circulation hemodynamics in vivo.Serum NO concentra-tions and blood gas analysis were measured.Results:Under normoxia,mean arterial pressure and total peripheral vascular resist-ance were increased,and ascending aortic blood flow and serum NO concentration were decreased in the L-NAME and AG groups.During hypoxia,pulmonary arterial pressure and pulmonary vascular resistance were significantly increased in the L-NAME and AG groups.Conclusions:This compensatory mechanism activated by inducible NOS and en-dothelial NOS effectively counteracts the pulmonary hemodynamic changes induced by hypoxic stress.It plays a crucial role in alleviating hypoxia-induced pulmonary arte-rial hypertension.展开更多
Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances ar...Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances are far from practical needs due to the lack of efficient electrocatalysts.Engineering the lattice of metal-based nanomaterials via phase control has emerged as an effective strategy to modulate their intrinsic electrocatalytic properties.Herein,we realize boron(B)-insertion-induced phase regulation of rhodium(Rh)nanocrystals to obtain amorphous Rh_(4)B nanoparticles(NPs)and hexagonal close-packed(hcp)RhB NPs through a facile wet-chemical method.A high Faradaic efficiency(92.1±1.2%)and NH_(3) yield rate(629.5±11.0μmol h^(−1) cm^(−2))are achieved over hcp RhB NPs,far superior to those of most reported NORR nanocatalysts.In situ spectro-electrochemical analysis and density functional theory simulations reveal that the excellent electrocatalytic performances of hcp RhB NPs are attributed to the upshift of d-band center,enhanced NO adsorption/activation profile,and greatly reduced energy barrier of the rate-determining step.A demonstrative Zn-NO battery is assembled using hcp RhB NPs as the cathode and delivers a peak power density of 4.33 mW cm−2,realizing simultaneous NO removal,NH3 synthesis,and electricity output.展开更多
OBJECTIVE:To explore the therapeutic effect and target of atractylenolide I(AT-I)on post-infectious irritable bowel syndrome(PI-IBS)rats.METHODS:Therefore,the preliminarily mechanism of AT-I in anti-PI-IBS were first ...OBJECTIVE:To explore the therapeutic effect and target of atractylenolide I(AT-I)on post-infectious irritable bowel syndrome(PI-IBS)rats.METHODS:Therefore,the preliminarily mechanism of AT-I in anti-PI-IBS were first predicted by network pharmacology and molecular docking,then the possible signaling pathways were systematically analyzed.Finally,the potential therapeutic targets and possible signaling pathways of AT-I on PI-IBS in Sprague-Dawley(SD)rat model were verified by experiments.RESULTS:AT-I could alleviate PI-IBS symptoms and reduce the expression of tumor necrosis factorα,interleukin-6 and Interferon-gamma in PI-IBS SD rat model and inhibit the c-Jun N-terminal kinase/inducible nitric oxide synthase(JNK/iNOS)pathway.Notably,AT-I treatment could inhibit the overexpression of polymeraseⅠand transcript release factor(PTRF).CONCLUSION:AT-I could alleviate PI-IBS symptoms through downregulation of PTRF and inhibiting the JNK/iNOS pathway.This study not only provides a scientific basis to clarify the anti-PI-IBS effect of AT-I and its mechanism but also suggests a novel promising therapeutic strategy to treat the PI-IBS.展开更多
BACKGROUND Esophageal cancer(ESCA)is among the most prevalent and lethal tumors globally.While nitric oxide synthase 1(NOS1)is recognized for its important in-volvement in various cancers,its specific function in ESCA...BACKGROUND Esophageal cancer(ESCA)is among the most prevalent and lethal tumors globally.While nitric oxide synthase 1(NOS1)is recognized for its important in-volvement in various cancers,its specific function in ESCA remains unclear.AIM To explore the potential role and underlying mechanisms of NOS1 in ESCA.METHODS Survival rates were analyzed using GeneCards and Gene Expression Profiling Interactive Analysis.The effects and mechanisms of NOS1 on ESCA cells were evaluated via the Cell Counting Kit-8 assay,scratch assay,Transwell assay,flow cytometry,quantitative polymerase chain reaction,western blotting,and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling staining.The protein interaction network was used to screen the interacting proteins of NOS1 and validate these interactions through co-immuno-precipitation and dual luciferase assays.Additionally,a nude mouse xenograft model was established to evaluate the effect of NOS1 in vivo.RESULTS The survival rate of patients with ESCA with high NOS1 expression was higher than that of patients with low NOS1 expression.NOS1 expression in ESCA cell lines was lower than that in normal esophageal epithelial cells.Overexpression of NOS1(oe-NOS1)inhibited proliferation,invasion,and migration abilities in ESCA cell lines,resulting in decreased autophagy levels and increased apoptosis,pyroptosis,and ferroptosis.Protein interaction studies confirmed the interaction between NOS1 and NOS1 adaptor protein(NOS1AP).Following oe-NOS1 and the silencing of NOS1AP,levels of P62 and microtubule-associated protein 1 light chain 3 beta increased both in vitro and in vivo.Furthermore,the expression levels of E-cadherin,along with the activation of phosphatidylinositol 3-kinase(PI3K)and protein kinase B(AKT),were inhibited in ESCA cell lines.CONCLUSION NOS1 and NOS1 proteins interact to suppress autophagy,activate the PI3K/AKT pathway,and exert anti-cancer effects in ESCA.展开更多
Neuronal nitric oxide synthase （nNOS） is mainly expressed in neurons,to some extent in astrocytes and neuronal stem cells.The alternative splicing of nNOS mRNA generates 5 isoforms of nNOS,including nNOS-,nNOS-,nNOS...Neuronal nitric oxide synthase （nNOS） is mainly expressed in neurons,to some extent in astrocytes and neuronal stem cells.The alternative splicing of nNOS mRNA generates 5 isoforms of nNOS,including nNOS-,nNOS-,nNOS-,nNOS-and nNOS-2.Monomer of nNOS is inactive,and dimer is the active form.Dimerization requires tetrahydrobiopterin （BH 4）,heme and L-arginine binding.Regulation of nNOS expression relies largely on cAMP response element-binding protein （CREB） activity,and nNOS activity is regulated by heat shock protein 90 （HSP90）/HSP70,calmodulin （CaM）,phosphorylation and dephosphorylation at Ser847 and Ser1412,and the protein inhibitor of nNOS （PIN）.There are primarily 9 nNOS-interacting proteins,including post-synaptic density protein 95 （PSD95）,clathrin assembly lymphoid leukemia （CALM）,calcium/calmodulindependent protein kinase II alpha （CAMKIIA）,Disks large homolog 4 （DLG4）,DLG2,6-phosphofructokinase,muscle type （PFK-M）,carboxy-terminal PDZ ligand of nNOS （CAPON） protein,syntrophin and dynein light chain （LC）.Among them,PSD95,CAPON and PFK-M are important nNOS adapter proteins in neurons.The interaction of PSD95 with nNOS controls synapse formation and is implicated in N-methyl-D-aspartic acid-induced neuronal death.nNOS-derived NO is implicated in synapse loss-mediated early cognitive/motor deficits in several neuropathological states,and negatively regulates neurogenesis under physiological and pathological conditions.展开更多
Objective: To investigate the association of Glu298Asp polymorphism of theeNOS gene with essential hypertension in elderly people. Methods: Ninety-five cases of essentialhypertension were randomly chosen from outpatie...Objective: To investigate the association of Glu298Asp polymorphism of theeNOS gene with essential hypertension in elderly people. Methods: Ninety-five cases of essentialhypertension were randomly chosen from outpatients and inpatients as the study group, and an equalnumber of sexes, age-matched healthy people as the control group. Their height, weight and bloodpressure were recorded and their fasting plasma lipid concentrations were measured. Glu298Asppolymorphism of the eNOS gene was measured using the methods of PCR and RFLP. Results: Theconstituent ratio of Genotype Glu/Asp in the study group (26.3%) was higher than that in the controlgroup (12.6%, x^2 = 5. 67, P<0.05), the allelic frequency of 298Asp in the study group (13.2%) wassignificantly higher than that in the control group (6.3%, x^2 = 5.06, P<0.05). Conclusion: Glu298Asp variant of the eNOS gene may be an independent predictor in essential hypertension.展开更多
With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic...With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate.However,few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients.Similarly in Alzheimer’s disease and other neurological disorders,synaptic dysfunction is recognized as the main reason for cognitive decline.Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system.Recently,nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia.This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction,neuroinflammation,oxidative stress,and blood-brain barrier dysfunction that underlie the progress of vascular dementia.Additionally,we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.展开更多
Nitric oxide(NO)is a gaseous molecule produced by 3 different NO synthase(NOS)isoforms:Neural/brain NOS(nNOS/bNOS,type 1),endothelial NOS(eNOS,type 3)and inducible NOS(type 2).Type 1 and 3 NOS are constitutively expre...Nitric oxide(NO)is a gaseous molecule produced by 3 different NO synthase(NOS)isoforms:Neural/brain NOS(nNOS/bNOS,type 1),endothelial NOS(eNOS,type 3)and inducible NOS(type 2).Type 1 and 3 NOS are constitutively expressed.NO can serve different purposes:As a vasoactive molecule,as a neurotransmitter or as an immunomodulator.It plays a key role in cerebral ischemia/reperfusion injury(CIRI).Hypoxic episodes simulate the production of oxygen free radicals,leading to mitochondrial and phospholipid damage.Upon reperfusion,increased levels of oxygen trigger oxide synthases;whose products are associated with neuronal damage by promoting lipid peroxidation,nitrosylation and excitotoxicity.Molecular pathways in CIRI can be altered by NOS.Neuroprotective effects are observed with eNOS activity.While nNOS interplay is prone to endothelial inflammation,oxidative stress and apoptosis.Therefore,nNOS appears to be detrimental.The interaction between NO and other free radicals develops peroxynitrite;which is a cytotoxic agent.It plays a main role in the likelihood of hemorrhagic events by tissue plasminogen activator(t-PA).Peroxynitrite scavengers are currently being studied as potential targets to prevent hemorrhagic transformation in CIRI.展开更多
AIM:Cydooxygenases (COX) are key enzymes for conversion of arachidonic acid to prostaglandins.Nitric oxide synthase (NOS) is the enzyme responsible for formation of nitric oxide. Both have constitutive and inducible i...AIM:Cydooxygenases (COX) are key enzymes for conversion of arachidonic acid to prostaglandins.Nitric oxide synthase (NOS) is the enzyme responsible for formation of nitric oxide. Both have constitutive and inducible isoforms.The inducible isoforms (iNOS and COX-2) are of great interest as regulators of tumor angiogenesis,tumorigenesis and inflammatory processes.This study was to clarify their role in pancreatic adenocarcinomas. METHODS:We investigated the immunohistochemical iNOS and COX-2 expression in 40 pancreatic ductal adenocardnomas of different grade and stage.The results were compared with microvessel density and dinicopathological data. RESULTS:Twenty-one (52.5%) of the cases showed iNOS expression,15 (37.5%) of the cases were positive for COX-2. The immunoreaction was heterogeneously distributed within the tumors.Staining intensity was different between the tumors.No correlation between iNOS and COX-2 expression was seen.There was no relationship with microvessel density. However,iNOS positive tumors developed more often distant metastases and the more malignant tumors showed a higher COX-2 expression.There was no correlation with other clinicopathological data. CONCLUSION:Approximately half of the cases expressed iNOS and COX-2.These two enzymes do not seem to be the key step in angiogenesis or carcinogenesis of pancreatic adenocarcinomas.Due to a low prevalence of COX-2 expression,chemoprevention of pancreatic carcinomas by COX-2 inhibitors can only achieve a limited success.展开更多
Aim： To investigate the effect of icariin on erectile function and the expression of nitric oxide synthase （NOS） isoforms in castrated rats. Methods： Thirty-two adult male Wistar rats were randomly divided into on...Aim： To investigate the effect of icariin on erectile function and the expression of nitric oxide synthase （NOS） isoforms in castrated rats. Methods： Thirty-two adult male Wistar rats were randomly divided into one shamoperated group （A） and three castrated groups （B, C and D）. One week after surgery, rats were treated with normal saline （groups A and B） or oral icariin （1 mg/[kg·day] for group C and 5 mg/[kg·day] for group D） for 4 weeks. One week after treatment, the erectile function of the rats was assessed by measuring intracavernosal pressure （ICP） during electrostimulation of the cavernosal nerve. The serum testosterone （ST） levels, the percent of smooth muscle （PSM） in trabecular tissue, and the expression of mRNA and proteins of neuronal nitric oxide synthase （nNOS）, inducible nitric oxide synthase （iNOS）, endothelial nitric oxide synthase （eNOS） and phosphodiesterase V （PDES） in corpus cavernosum （CC） were also evaluated. Results： ICP, PSM, ST and the expression of nNOS, iNOS, eNOS and PDE5 were significantly decreased in group B compared with those in group A （P 〈 0.01）. However, ICE PSM and the expression of nNOS and iNOS were increased in groups C and D compared with those in group B （P 〈 0.05）. Changes in ST and the expression of eNOS and PDE5 were not significant （P 〉 0.05） in groups C and D compared with those in group B. Conclusion： Oral treatment with icariin （〉 98.6 % purity） for 4 weeks potentially improves erectile function. This effect is correlated with an increase in PSM and the expression of certain NOS in the CC of castrated rats. These results suggest that icariin may have a therapeutic effect on erectile dysfunction.展开更多
AIM： To determine the expressions of inducible nitric oxide synthase （iNOS） and matrix metalloproteinase-9 （MMP-9） in hepatocellular carcinoma （HCC） and to investigate the relationship between iNOS and MMP-9 ex...AIM： To determine the expressions of inducible nitric oxide synthase （iNOS） and matrix metalloproteinase-9 （MMP-9） in hepatocellular carcinoma （HCC） and to investigate the relationship between iNOS and MMP-9 expression and their effects on angiogenesis and progression of HCC.METHODS： In this study, we examined iNOS, MMP-9, and CD34 expression in specimens surgically removed from 32 HCC patients and 7 normal liver tissues by immunohistochemical staining. Meanwhile, microvessel density （MVD） was determined as a marker of angiogenesis by counting CD34-positive cells. RESULTS： The positive rates of iNOS and MMP-9 expression were 71.88% （23/32） and 78.13% （25/32） in HCC. MMP-9 expression was significantly correlated with tumor size, capsule status, TNM stage, and risk of HCC recurrence （P = 0.032, P= 0.033, P= 0.007, and P= 0.001, respectively）. There was also a significant relationship between iNOS expression and capsule status and risk of HCC recurrence （P = 0.049 and P = 0.004, respectively）, but no correlation between iNOS expression and tumor size and TNM stage. There was a positive association between MVD and TNM stage and risk of HCC recurrence （P = 0.037 and P = 0.000, respectively）. The count of MVD was significantly different in different iNOS and MMP-9 immunoreactivity groups （F= 17.713 and 17.097, P= 0.000 and P = 0.000, respectively）. The examination of Spearman＇s rank correlation coefficient showed that there was a significant positive correlation between MVD and iNOS, MMP-9 immunoreactivity （r = 0.754 and 0.751, P= 0.000 and P=-0.000, respectively）. There was also a significant association between MMP-9 and iNOS expression in HCC （P = 0.010）. CONCLUSION： Nitric oxide （NO） produced by iNOS could modulate MMP-9 production and therefore contribute totumor cell angiogenesis and invasion and metastasis in HCC. The strong expression of iNOS and MMP-9 in HCC may be helpful in evaluating the recurrence of HCC, predicting poor prognosis. For patients with strong expression of MMP-9 and iNOS, the optimal treatment scheme needs to be selected.展开更多
AIM： Portal hypertension is a common complication of liver cirrhosis. Intrahepatic pressure can be elevated in several ways. Abnormal architecture affecting the vasculature, an increase in vasoconstrictors and increa...AIM： Portal hypertension is a common complication of liver cirrhosis. Intrahepatic pressure can be elevated in several ways. Abnormal architecture affecting the vasculature, an increase in vasoconstrictors and increased circulation from the splanchnic viscera into the portal system may all contribute. It follows that endogenous vasodilators may be able to alleviate the hypertension. We therefore aimed to investigate the levels of endogenous vasodilators, nitric oxide （NO） and carbon monoxide （CO） through the expression of nitric oxide synthase （NOS） and heme oxygenase （HO）. METHOD： Cirrhotic （n = 20） and non-cirrhotic （n = 20） livers were obtained from patients who had undergone surgery. The mRNA and protein expressions of the various isoforms of NOS and HO were examined using competitive PCR, Western Blot and immunohistochemistry. RESULTS： There was no significant change in either inducible NOS （iNOS） or neuronal NOS （nNOS） expressions while endothelial NOS （eNOS） was up- regulated in cirrhotic livers. Concomitantly, caveolin-1, an established down-regulator of eNOS, was upregulated. Inducible HO-1 and constitutive HO-2 were found to show increased expression in cirrhotic livers albeit in different Iocalizations. CONCLUSION： The differences of NOS expression might be due to their differing roles in maintaining liver homeostasis and/or involvement in the pathology of cirrhosis. Sheer stress within the hypertensive liver may induce increased expression of eNOS. In turn, caveolin-1 is also increased. Whether this serves as a defense mechanism against further cirrhosis or is a consequence of cirrhosis, is yet unknown. The elevated expression of HO-1 and HO-2 suggest that CO may compensate in its role as a vasodilator albeit weakly. It is possible that CO and NO have parallel or coordinated functions within the liver and may work antagonistically in the pathophysiology of portal hypertension.展开更多
OBJECTIVE： To explore the long-term effects and pain relief mechanism of acupotomy by observing changes in nitric oxide synthase （NOS） and beta-en- dorphin （~3-EP） in the hypothalamus, spinal cord, and peripheral...OBJECTIVE： To explore the long-term effects and pain relief mechanism of acupotomy by observing changes in nitric oxide synthase （NOS） and beta-en- dorphin （~3-EP） in the hypothalamus, spinal cord, and peripheral blood of rats with third lumbar ver- tebrae （L3） transverse process syndrome. METHODS： Twenty-eight SD rats were randomly as- signed to normal, model, electroacupuncture （EA）, and acupotomy group. The last three groups were put through an operation to emulate L3 transverse process syndrome. Fourteen days after the simulation operation, EA and acupotomy treatments were applied to the respective groups. Fifty-six days afterthe simulation operation, biochemistry tests and enzyme-linked immunosorbent assay were used to measure NOS and 13-EP in the hypothalamus, spinal cord, and peripheral blood. RESULTS： Rats with the simulation operation showed significantly higher levels of NOS and II3-EP in the hypothalamus, spinal cord, and peripheral blood than those in the normal group. The EA and acupotomy groups had significantly lower levels of NOS and β-EP than those in the model group. There was no statistical difference between the EA and acupotomy groups. CONCLUSION： EA and acupotomy treatments significantly lowered NOS and β-EP levels in the hypothalamus, spinal cord, and peripheral blood and alleviated L3 transverse process syndrome.展开更多
AIM: To study the distribution of nitric oxide synthase (NOS) in rat stomach myenteric plexus. METHODS: The distribution of NOS in gastric wall was studied in quantity and location by the NADPH-diaphorase (NDP) histoc...AIM: To study the distribution of nitric oxide synthase (NOS) in rat stomach myenteric plexus. METHODS: The distribution of NOS in gastric wall was studied in quantity and location by the NADPH-diaphorase (NDP) histochemical staining method and whole mount preparation technique. RESULTS: NOS was distributed in whole stomach wall, most of them were located in myenteric plexus, and distributed in submucosal plexus.The shape of NOS positive neurons was basically similar, most of them being round and oval in shape. But their density, size and staining intensity varied greatly in the different parts of stomach. The density was 62+/-38 cells mm(2) (antrum), 43+/-32 cells/mm(2) (body), and 32+/-28 cells mm(2) (fundus), respectively. The size and staining intensity of NOS positive neurons in the fundus were basically the same, the neurons being large and dark stained, while they were obviously different in antrum. In the body of the stomach, the NOS positive neurons were in an intermediate state from fundus to antrum. There were some beadlike structures which were strung together by NOS positive varicosities in nerve fibers, some were closely adherent to the outer walls of blood vessels. CONCLUSION: Nitric oxide might be involved in the modulation of motility, secretion and blood circulation of the stomach, and the significant difference of NOS positive neurons in different parts of stomach myenteric plexus may be related to the physiologic function of stomach.展开更多
AIM: To investigate the expression of NOS in gastric carcinoma, and to explore the relationship between the expression of nitric oxide synthases (NOS) and p53, PCNA,pathological features and clinical staging of gastri...AIM: To investigate the expression of NOS in gastric carcinoma, and to explore the relationship between the expression of nitric oxide synthases (NOS) and p53, PCNA,pathological features and clinical staging of gastric cancer.METHODS: The activity of NOS protein was investigated in 85 samples of human gastric carcinoma and 25 samples of normal gastric mucosal tissue by biochemical assay. We then examined the expression of NOS, p53, PCNA in 85 samples of human gastric cancer was examined by immunohistochemistry, and NOS mRNA expression in 85 gastric cancer tissue specimens by in situ hybridization.RESULTS: Biochemical assay showed that the activity of NOS was significantly higher in gastric carcinoma than in normal gastric mucosal tissues (t = 0.4161, P＜0.01).Immunohistochemistry revealed that endothelial nitric oxide synthase (eNOS) expressed in all samples of normal gastric mucosa, but only 6 cases of 85 gastric cancer specimens showed weak positive immunohistochemical reactions to eNOS (20%). Inducible nitric oxide synthase (iNOS) was expressed strongly in human gastric carcinoma (81.2%). In situ hybridization analysis showed that iNOS mRNA expression was significantly stronger than eNOS mRNA expression in gastric cancer tissue (x2 = 10.23, P＜0.01). The expression of iNOS in gastric cancer was associated with differentiation, clinical stages or lymph node metastases (r= 0.3426, P＜0.05). However,iNOS expression did not correlate with histological classifications and morphological types. The expression of iNOS was significantly correlated with p53 or PCNA expression (r = 0.3612, P＜0.05). The expression of neuronal nitric oxide synthase (nNOS) was not examined by immunohistochemistry and in situ hybridization in gastric cancer specimens and normal gastric mucosa.CONCLUSION: In human gastric cancer, there is an enhanced expression of iNOS, but not of eNOS. NOS promotes the proliferation of tumor cells and plays an important role in gastric cancer spread. Inactivation of antioncogene p53 and overexpression of iNOS might play a synergetic role in the process of carcinogenesis of human gastric carcinoma.展开更多
AIM： TO investigate the dynamic change and role of neuronal nitric oxide synthase （nNOS） and inducible nitric oxide synthase （iNOS） in neonatal rat with intestinal injury and to define whether necrotizing enteroc...AIM： TO investigate the dynamic change and role of neuronal nitric oxide synthase （nNOS） and inducible nitric oxide synthase （iNOS） in neonatal rat with intestinal injury and to define whether necrotizing enterocolitis （NEC） is associated with the levels of nitric oxide synthase （NOS） in the mucosa of the affected intestine tissue. METHODS： Wistar rats less than 24 h in age received an intraperitoneal injection with 5 mg/kg lipopolysaccharide （LPS）. Ileum tissues were collected at 1, 3, 6, 12 and 24 h following LPS challenge for histological evaluation of NEC and for measurements of nNOS and iNOS. The correlation between the degree of intestinal injury and levels of NOS was determined. RESULTS： The LPS-injected increase in injury scores pups showed a significant versus the control. The expression of nNOS protein and mRNA was diminished after LPS injection. There was a negative significant correlation between the nNOS protein and the grade of median intestinal injury within 24 h. The expression of iNOS protein and mRNA was significantly increased in the peak of intestinal injury. CONCLUSION： nNOS and iNOS play different roles in LPS-induced intestinal injury. Caution should be exerted concerning potential therapeutic uses of NOS inhibitors in NEC.展开更多
Objective: The present study is designed to investigate the cellular expressions and immunolocalizations of three different nitric oxide synthase (NOS) isoforms and the related nitric oxide (NO)/cyclic guanosine monop...Objective: The present study is designed to investigate the cellular expressions and immunolocalizations of three different nitric oxide synthase (NOS) isoforms and the related nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway in the ovaries of neonatal and immature rats.Methods: The ovaries were obtained from ICR (Institute for Cancer Research) female Sprague-Dawley rats at postnatal days 1,5,7,10,and 19.Then we carried out the histologic examination,immunohistochemistry,measurement of NOS activity,and modifications within the NO/cGMP pathway.Results: During postnatal days 1,5,7,10,and 19,all three isoforms of NOS were mainly localized to the oocytes and expressed as a gradual increase in granulosa cells and theca cells within the growing follicle.The ovarian total NOS activities and NO levels were increased at postnatal days 7 and 10 compared with other days.Conclusions: Our findings suggest that the locally produced NO and the NO/NOS signaling systems are involved in the follicular development to puberty.展开更多
AIM: To study the distribution of the constitutive nitric oxide synthase (NOS) in the jejunum of adult rat. METHODS: The distribution of endothelial NOS (eNOS) was detected by immunohistochemistry. Immunofluorescence ...AIM: To study the distribution of the constitutive nitric oxide synthase (NOS) in the jejunum of adult rat. METHODS: The distribution of endothelial NOS (eNOS) was detected by immunohistochemistry. Immunofluorescence histochemical dual staining technique were used for studying the distribution of neuronal NOS (nNOS) and eNOS. The dual stained slides were observed under a confocal laser scanning microscope. RESULTS: Positive neuronal NOS (nNOS) and endothelial NOS (eNOS) cells were found to be distributed in lamina propria of villi, and the epithelial cell was not stained. eNOS was mainly located in submucosal vascular endothelia, while nNOS was mainly situated in myenteric plexus. Some cells in the villi had both nNOS and eNOS. More than 80% of the cells were positive for both nNOS and eNOS, the rest cells were positive either for nNOS or for eNOS. CONCLUSION: The two constitutive nitric oxide synthases are distributed differently in the jejunum of rat. nNOS distributed in myenteric plexus is a neurotransmitter in the non-adrenergic non-cholinergic (NANC) inhibitory nerves. eNOS distributed in endothelial and smooth muscle cells of blood vessels plays vasodilator role. eNOS and nNOS are coexpressed in some cells of lamina propria of villi. NO generated by those NOS is very important in the physiological and pathological process of small intestine.展开更多
In this study, we examined the expression of inducible nitric oxide s ynthase (iNOS) and vascular endothelial growth factor (VEGF) by immunohistoc hemi cal staining in 76 tissue sections collected from hepatocellula...In this study, we examined the expression of inducible nitric oxide s ynthase (iNOS) and vascular endothelial growth factor (VEGF) by immunohistoc hemi cal staining in 76 tissue sections collected from hepatocellular carcinoma (HCC) patients undergoing hepatectomy. Microvascular density (MVD) was determined by counting endothelial cells immunostained using anti-CD34 antibody. We performe d DNA-flow cytometric analyses to elucidate the impact of iNOS and VEGF expressi o n on the cell cycle of HCC. Most of the HCC cells that invaded stroma were mark edly immunostained by iNOS antibody. The iNOS stain intensity of the liver tissu e close to the tumor edge was stronger than that of HCC tissue, and the stronges t was the hepatocytes closer to the tumor tissue. However, iNOS expression in 10 normal hepatic samples was undetectable. VEGF positive expression ratio was 84. 8% in iNOS positive expression cases, and the ratio was 35.3% in negative cases. There was significant correlation (P=0.000) between iNOS and VEGF expressi on. Moreover, iNOS expression was significantly associated with bcl-2 and MVD, but w ithout p53 expression. DNA-flow cytometric analyses showed that combined expres s ion of iNOS and VEGF had significant impact on the cell cycle in HCC. PI (Proli ferating Index) and SPF (S-phase fraction) in the combined positive expression o f iNOS and VEGF group was significantly higher than that in the combined negativ e group. The present findings suggested that iNOS expression was significantly a ssociated with angiogenesis, bcl-2 and cell proliferation of HCC.展开更多
BACKGROUND： Accumulated evidence indicates an important role for hippocampal dendrite atrophy in development of depression, while brain-derived neurotrophic factor （BDNF） participates in hippocampal dendrite growth...BACKGROUND： Accumulated evidence indicates an important role for hippocampal dendrite atrophy in development of depression, while brain-derived neurotrophic factor （BDNF） participates in hippocampal dendrite growth. OBJECTIVE： To discuss the role of BDNF and neuronal nitric oxide synthase （nNOS） in chronic and unpredictable stress-induced depression and the pathogenesis of depression. DESIGN, TIME AND SETTING： Randomized, controlled animal experiment. The experiment was carded out from October 2006 to May 2007 at the Department of Animal Physiology, College of Life Science, Shaanxi Normal University. MATERIALS： Thirty-seven male Sprague-Dawley rats weighing 250-300 g at the beginning of the experiment were obtained from Shaanxi Provincial Institute of Traditional Chinese Medicine （Xi＇an, China）. BDNF antibody and nNOS antibody were provided by Santa Cruz （USA）. K252a （BDNF inhibitor） and 7-NI （nNOS inhibitor） were provided by Sigma （USA）. METHODS： Animals were randomly divided into five groups： Control group, chronic unpredicted mild stress （CUMS） group, K252a group, K252a＋7-NI group and 7-NI＋CUMS group. While the Control, K252a and K252a＋7-NI groups of rats not subjected to stress had free access to food and water, other groups of rats were subjected to nine stressors randomly applied for 21 days, with each stressor applied 2-3 times. On days 1, 7, 14 and 21 during CUMS, rats received microinjection of 1 μL of physiological saline in the Control and CUMS groups, 1 ~ L of K252a in the K252a group, 1 μL of K252a and 7-NI in the K252a＋7-NI group, and 1 μL of 7-NI in the 7-NI＋CUMS group. We observed a variety of alterations in sucrose preference, body weight change, open field test and forced swimming test, and observed the expression of BDNF and nNOS in rat hippocampus by immunohistochemistry; MAIN OUTCOME MEASURES： ① A variety.of behavioral alterations of rats; ② The expression of BDNF and nNOS in rat hippocampus. RESULTS： Compared with the Control group, the behavior of the CUMS rats was significantly depressed, the expression of BDNF decreased （P 〈 0.01） but the expression of nNOS increased （P 〈 0.01）. The behavior of rats given intra-hippocampal injection of BDNF inhibitor was significantly depressed and the expression of nNOS was significantly increased （P 〈 0.01）. Intra-hippocampal injections of an nNOS inhibitor reversed the depression-like behavioral changes induced by CUMS or intra-hippocampal injection of BDNF inhibitor. CONCLUSION： CUMS induced a decrease in expression of BDNF and an increase in expression of NO in the hippocampus, which may lead to depression.展开更多
基金This work was supported by the National Natural Science Foundation of China(grant numbers 81560301 and 81160012)the Natural Science Foundation of Qinghai Province(grant number 2022-ZJ-905)‘2022 Qinghai Province Kunlun Talents High-end Innovation and Entrepreneurship Talents’Outstanding Talent Project.
文摘Background:Under hypoxia,exaggerated compensatory responses may lead to acute mountain sickness.The excessive vasodilatory effect of nitric oxide(NO)can lower the hypoxic pulmonary vasoconstriction(HPV)and peripheral blood pressure.While NO is catalyzed by various nitric oxide synthase(NOS)isoforms,the regulatory roles of these types in the hemodynamics of pulmonary and systemic circulation in living hypoxic animals remain unclear.Therefore,this study aims to investigate the regu-latory effects of different NOS isoforms on pulmonary and systemic circulation in hypoxic rats by employing selective NOS inhibitors and continuously monitoring hemodynamic parameters of both pulmonary and systemic circulation.Methods:Forty healthy male Sprague–Dawley(SD)rats were randomly divided into four groups:Control group(NG-nitro-D-arginine methyl ester,D-NAME),L-NAME group(non-selective NOS inhibitor,NG-nitro-L-arginine methyl ester),AG group(in-ducible NOS inhibitor group,aminoguanidine),and 7-NI group(neurological NOS in-hibitor,7-nitroindazole).Hemodynamic parameters of rats were monitored for 10 min after inhibitor administration and 5 min after induction of hypoxia[15%O2,2200 m a.sl.,582 mmHg(76.5 kPa),Xining,China]using the real-time dynamic monitoring model for pulmonary and systemic circulation hemodynamics in vivo.Serum NO concentra-tions and blood gas analysis were measured.Results:Under normoxia,mean arterial pressure and total peripheral vascular resist-ance were increased,and ascending aortic blood flow and serum NO concentration were decreased in the L-NAME and AG groups.During hypoxia,pulmonary arterial pressure and pulmonary vascular resistance were significantly increased in the L-NAME and AG groups.Conclusions:This compensatory mechanism activated by inducible NOS and en-dothelial NOS effectively counteracts the pulmonary hemodynamic changes induced by hypoxic stress.It plays a crucial role in alleviating hypoxia-induced pulmonary arte-rial hypertension.
基金funding support from General Research Fund[Project No.14300525]from the Research Grants Council(RGC)of Hong Kong SAR,Chinafunding support from Natural Science Foundation of China(NSFC)Young Scientists Fund(Project No.22305203)+2 种基金NSFC Projects Nos.22309123,22422303,22303011,22033002,92261112 and U21A20328support from the Hong Kong Branch of National Precious Metals Material Engineering Research Center(NPMM)at City University of Hong Kongsupport from Young Collaborative Research Grant[Project No.C1003-23Y]support from RGC of Hong Kong SAR,China.
文摘Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances are far from practical needs due to the lack of efficient electrocatalysts.Engineering the lattice of metal-based nanomaterials via phase control has emerged as an effective strategy to modulate their intrinsic electrocatalytic properties.Herein,we realize boron(B)-insertion-induced phase regulation of rhodium(Rh)nanocrystals to obtain amorphous Rh_(4)B nanoparticles(NPs)and hexagonal close-packed(hcp)RhB NPs through a facile wet-chemical method.A high Faradaic efficiency(92.1±1.2%)and NH_(3) yield rate(629.5±11.0μmol h^(−1) cm^(−2))are achieved over hcp RhB NPs,far superior to those of most reported NORR nanocatalysts.In situ spectro-electrochemical analysis and density functional theory simulations reveal that the excellent electrocatalytic performances of hcp RhB NPs are attributed to the upshift of d-band center,enhanced NO adsorption/activation profile,and greatly reduced energy barrier of the rate-determining step.A demonstrative Zn-NO battery is assembled using hcp RhB NPs as the cathode and delivers a peak power density of 4.33 mW cm−2,realizing simultaneous NO removal,NH3 synthesis,and electricity output.
基金The University Collaborative Innovation Project of Anhui:Creation of a Combined Animal Model of Coronary Heart Disease based on the Theory of Xin'an Medicine(No.GXXT-2020-024)Start-up Funding for Doctoral Research at Wannan Medical College(WYRCQD2018009)Horizontal Project of South Anhui Medical College(H202003)。
文摘OBJECTIVE:To explore the therapeutic effect and target of atractylenolide I(AT-I)on post-infectious irritable bowel syndrome(PI-IBS)rats.METHODS:Therefore,the preliminarily mechanism of AT-I in anti-PI-IBS were first predicted by network pharmacology and molecular docking,then the possible signaling pathways were systematically analyzed.Finally,the potential therapeutic targets and possible signaling pathways of AT-I on PI-IBS in Sprague-Dawley(SD)rat model were verified by experiments.RESULTS:AT-I could alleviate PI-IBS symptoms and reduce the expression of tumor necrosis factorα,interleukin-6 and Interferon-gamma in PI-IBS SD rat model and inhibit the c-Jun N-terminal kinase/inducible nitric oxide synthase(JNK/iNOS)pathway.Notably,AT-I treatment could inhibit the overexpression of polymeraseⅠand transcript release factor(PTRF).CONCLUSION:AT-I could alleviate PI-IBS symptoms through downregulation of PTRF and inhibiting the JNK/iNOS pathway.This study not only provides a scientific basis to clarify the anti-PI-IBS effect of AT-I and its mechanism but also suggests a novel promising therapeutic strategy to treat the PI-IBS.
基金Supported by the National Natural Science Foundation of China,No.81000201.
文摘BACKGROUND Esophageal cancer(ESCA)is among the most prevalent and lethal tumors globally.While nitric oxide synthase 1(NOS1)is recognized for its important in-volvement in various cancers,its specific function in ESCA remains unclear.AIM To explore the potential role and underlying mechanisms of NOS1 in ESCA.METHODS Survival rates were analyzed using GeneCards and Gene Expression Profiling Interactive Analysis.The effects and mechanisms of NOS1 on ESCA cells were evaluated via the Cell Counting Kit-8 assay,scratch assay,Transwell assay,flow cytometry,quantitative polymerase chain reaction,western blotting,and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling staining.The protein interaction network was used to screen the interacting proteins of NOS1 and validate these interactions through co-immuno-precipitation and dual luciferase assays.Additionally,a nude mouse xenograft model was established to evaluate the effect of NOS1 in vivo.RESULTS The survival rate of patients with ESCA with high NOS1 expression was higher than that of patients with low NOS1 expression.NOS1 expression in ESCA cell lines was lower than that in normal esophageal epithelial cells.Overexpression of NOS1(oe-NOS1)inhibited proliferation,invasion,and migration abilities in ESCA cell lines,resulting in decreased autophagy levels and increased apoptosis,pyroptosis,and ferroptosis.Protein interaction studies confirmed the interaction between NOS1 and NOS1 adaptor protein(NOS1AP).Following oe-NOS1 and the silencing of NOS1AP,levels of P62 and microtubule-associated protein 1 light chain 3 beta increased both in vitro and in vivo.Furthermore,the expression levels of E-cadherin,along with the activation of phosphatidylinositol 3-kinase(PI3K)and protein kinase B(AKT),were inhibited in ESCA cell lines.CONCLUSION NOS1 and NOS1 proteins interact to suppress autophagy,activate the PI3K/AKT pathway,and exert anti-cancer effects in ESCA.
基金supported by the National Natural Science Foundation of China(No. 30971021,81030023 and 30901550)
文摘Neuronal nitric oxide synthase （nNOS） is mainly expressed in neurons,to some extent in astrocytes and neuronal stem cells.The alternative splicing of nNOS mRNA generates 5 isoforms of nNOS,including nNOS-,nNOS-,nNOS-,nNOS-and nNOS-2.Monomer of nNOS is inactive,and dimer is the active form.Dimerization requires tetrahydrobiopterin （BH 4）,heme and L-arginine binding.Regulation of nNOS expression relies largely on cAMP response element-binding protein （CREB） activity,and nNOS activity is regulated by heat shock protein 90 （HSP90）/HSP70,calmodulin （CaM）,phosphorylation and dephosphorylation at Ser847 and Ser1412,and the protein inhibitor of nNOS （PIN）.There are primarily 9 nNOS-interacting proteins,including post-synaptic density protein 95 （PSD95）,clathrin assembly lymphoid leukemia （CALM）,calcium/calmodulindependent protein kinase II alpha （CAMKIIA）,Disks large homolog 4 （DLG4）,DLG2,6-phosphofructokinase,muscle type （PFK-M）,carboxy-terminal PDZ ligand of nNOS （CAPON） protein,syntrophin and dynein light chain （LC）.Among them,PSD95,CAPON and PFK-M are important nNOS adapter proteins in neurons.The interaction of PSD95 with nNOS controls synapse formation and is implicated in N-methyl-D-aspartic acid-induced neuronal death.nNOS-derived NO is implicated in synapse loss-mediated early cognitive/motor deficits in several neuropathological states,and negatively regulates neurogenesis under physiological and pathological conditions.
基金Supported by the National Science of Foundation of Jiangsu Province(BK 2001162)
文摘Objective: To investigate the association of Glu298Asp polymorphism of theeNOS gene with essential hypertension in elderly people. Methods: Ninety-five cases of essentialhypertension were randomly chosen from outpatients and inpatients as the study group, and an equalnumber of sexes, age-matched healthy people as the control group. Their height, weight and bloodpressure were recorded and their fasting plasma lipid concentrations were measured. Glu298Asppolymorphism of the eNOS gene was measured using the methods of PCR and RFLP. Results: Theconstituent ratio of Genotype Glu/Asp in the study group (26.3%) was higher than that in the controlgroup (12.6%, x^2 = 5. 67, P<0.05), the allelic frequency of 298Asp in the study group (13.2%) wassignificantly higher than that in the control group (6.3%, x^2 = 5.06, P<0.05). Conclusion: Glu298Asp variant of the eNOS gene may be an independent predictor in essential hypertension.
基金supported by the National Key R&D Program of China,No.2019YFE0121200(to LQZ)the National Natural Science Foundation of China,Nos.82325017(to LQZ),82030032(to LQZ),82261138555(to DL)+2 种基金the Natural Science Foundation of Hubei Province,No.2022CFA004(to LQZ)the Natural Science Foundation of Jiangxi Province,No.20224BAB206040(to XZ)Research Project of Cognitive Science and Transdisciplinary Studies Center of Jiangxi Province,No.RZYB202201(to XZ).
文摘With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate.However,few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients.Similarly in Alzheimer’s disease and other neurological disorders,synaptic dysfunction is recognized as the main reason for cognitive decline.Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system.Recently,nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia.This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction,neuroinflammation,oxidative stress,and blood-brain barrier dysfunction that underlie the progress of vascular dementia.Additionally,we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.
文摘Nitric oxide(NO)is a gaseous molecule produced by 3 different NO synthase(NOS)isoforms:Neural/brain NOS(nNOS/bNOS,type 1),endothelial NOS(eNOS,type 3)and inducible NOS(type 2).Type 1 and 3 NOS are constitutively expressed.NO can serve different purposes:As a vasoactive molecule,as a neurotransmitter or as an immunomodulator.It plays a key role in cerebral ischemia/reperfusion injury(CIRI).Hypoxic episodes simulate the production of oxygen free radicals,leading to mitochondrial and phospholipid damage.Upon reperfusion,increased levels of oxygen trigger oxide synthases;whose products are associated with neuronal damage by promoting lipid peroxidation,nitrosylation and excitotoxicity.Molecular pathways in CIRI can be altered by NOS.Neuroprotective effects are observed with eNOS activity.While nNOS interplay is prone to endothelial inflammation,oxidative stress and apoptosis.Therefore,nNOS appears to be detrimental.The interaction between NO and other free radicals develops peroxynitrite;which is a cytotoxic agent.It plays a main role in the likelihood of hemorrhagic events by tissue plasminogen activator(t-PA).Peroxynitrite scavengers are currently being studied as potential targets to prevent hemorrhagic transformation in CIRI.
文摘AIM:Cydooxygenases (COX) are key enzymes for conversion of arachidonic acid to prostaglandins.Nitric oxide synthase (NOS) is the enzyme responsible for formation of nitric oxide. Both have constitutive and inducible isoforms.The inducible isoforms (iNOS and COX-2) are of great interest as regulators of tumor angiogenesis,tumorigenesis and inflammatory processes.This study was to clarify their role in pancreatic adenocarcinomas. METHODS:We investigated the immunohistochemical iNOS and COX-2 expression in 40 pancreatic ductal adenocardnomas of different grade and stage.The results were compared with microvessel density and dinicopathological data. RESULTS:Twenty-one (52.5%) of the cases showed iNOS expression,15 (37.5%) of the cases were positive for COX-2. The immunoreaction was heterogeneously distributed within the tumors.Staining intensity was different between the tumors.No correlation between iNOS and COX-2 expression was seen.There was no relationship with microvessel density. However,iNOS positive tumors developed more often distant metastases and the more malignant tumors showed a higher COX-2 expression.There was no correlation with other clinicopathological data. CONCLUSION:Approximately half of the cases expressed iNOS and COX-2.These two enzymes do not seem to be the key step in angiogenesis or carcinogenesis of pancreatic adenocarcinomas.Due to a low prevalence of COX-2 expression,chemoprevention of pancreatic carcinomas by COX-2 inhibitors can only achieve a limited success.
基金The authors would like to acknowledge the National Nature Science Foundation of China(No.30070927)Beijing National Nature Science Foundation(No.7012023)for grants for this work.
文摘Aim： To investigate the effect of icariin on erectile function and the expression of nitric oxide synthase （NOS） isoforms in castrated rats. Methods： Thirty-two adult male Wistar rats were randomly divided into one shamoperated group （A） and three castrated groups （B, C and D）. One week after surgery, rats were treated with normal saline （groups A and B） or oral icariin （1 mg/[kg·day] for group C and 5 mg/[kg·day] for group D） for 4 weeks. One week after treatment, the erectile function of the rats was assessed by measuring intracavernosal pressure （ICP） during electrostimulation of the cavernosal nerve. The serum testosterone （ST） levels, the percent of smooth muscle （PSM） in trabecular tissue, and the expression of mRNA and proteins of neuronal nitric oxide synthase （nNOS）, inducible nitric oxide synthase （iNOS）, endothelial nitric oxide synthase （eNOS） and phosphodiesterase V （PDES） in corpus cavernosum （CC） were also evaluated. Results： ICP, PSM, ST and the expression of nNOS, iNOS, eNOS and PDE5 were significantly decreased in group B compared with those in group A （P 〈 0.01）. However, ICE PSM and the expression of nNOS and iNOS were increased in groups C and D compared with those in group B （P 〈 0.05）. Changes in ST and the expression of eNOS and PDE5 were not significant （P 〉 0.05） in groups C and D compared with those in group B. Conclusion： Oral treatment with icariin （〉 98.6 % purity） for 4 weeks potentially improves erectile function. This effect is correlated with an increase in PSM and the expression of certain NOS in the CC of castrated rats. These results suggest that icariin may have a therapeutic effect on erectile dysfunction.
文摘AIM： To determine the expressions of inducible nitric oxide synthase （iNOS） and matrix metalloproteinase-9 （MMP-9） in hepatocellular carcinoma （HCC） and to investigate the relationship between iNOS and MMP-9 expression and their effects on angiogenesis and progression of HCC.METHODS： In this study, we examined iNOS, MMP-9, and CD34 expression in specimens surgically removed from 32 HCC patients and 7 normal liver tissues by immunohistochemical staining. Meanwhile, microvessel density （MVD） was determined as a marker of angiogenesis by counting CD34-positive cells. RESULTS： The positive rates of iNOS and MMP-9 expression were 71.88% （23/32） and 78.13% （25/32） in HCC. MMP-9 expression was significantly correlated with tumor size, capsule status, TNM stage, and risk of HCC recurrence （P = 0.032, P= 0.033, P= 0.007, and P= 0.001, respectively）. There was also a significant relationship between iNOS expression and capsule status and risk of HCC recurrence （P = 0.049 and P = 0.004, respectively）, but no correlation between iNOS expression and tumor size and TNM stage. There was a positive association between MVD and TNM stage and risk of HCC recurrence （P = 0.037 and P = 0.000, respectively）. The count of MVD was significantly different in different iNOS and MMP-9 immunoreactivity groups （F= 17.713 and 17.097, P= 0.000 and P = 0.000, respectively）. The examination of Spearman＇s rank correlation coefficient showed that there was a significant positive correlation between MVD and iNOS, MMP-9 immunoreactivity （r = 0.754 and 0.751, P= 0.000 and P=-0.000, respectively）. There was also a significant association between MMP-9 and iNOS expression in HCC （P = 0.010）. CONCLUSION： Nitric oxide （NO） produced by iNOS could modulate MMP-9 production and therefore contribute totumor cell angiogenesis and invasion and metastasis in HCC. The strong expression of iNOS and MMP-9 in HCC may be helpful in evaluating the recurrence of HCC, predicting poor prognosis. For patients with strong expression of MMP-9 and iNOS, the optimal treatment scheme needs to be selected.
基金Supported by Research Biolabs Pte Ltd.Beatrice J Goh is a recipient of the Research Scholarship awarded by the National University of Singapore
文摘AIM： Portal hypertension is a common complication of liver cirrhosis. Intrahepatic pressure can be elevated in several ways. Abnormal architecture affecting the vasculature, an increase in vasoconstrictors and increased circulation from the splanchnic viscera into the portal system may all contribute. It follows that endogenous vasodilators may be able to alleviate the hypertension. We therefore aimed to investigate the levels of endogenous vasodilators, nitric oxide （NO） and carbon monoxide （CO） through the expression of nitric oxide synthase （NOS） and heme oxygenase （HO）. METHOD： Cirrhotic （n = 20） and non-cirrhotic （n = 20） livers were obtained from patients who had undergone surgery. The mRNA and protein expressions of the various isoforms of NOS and HO were examined using competitive PCR, Western Blot and immunohistochemistry. RESULTS： There was no significant change in either inducible NOS （iNOS） or neuronal NOS （nNOS） expressions while endothelial NOS （eNOS） was up- regulated in cirrhotic livers. Concomitantly, caveolin-1, an established down-regulator of eNOS, was upregulated. Inducible HO-1 and constitutive HO-2 were found to show increased expression in cirrhotic livers albeit in different Iocalizations. CONCLUSION： The differences of NOS expression might be due to their differing roles in maintaining liver homeostasis and/or involvement in the pathology of cirrhosis. Sheer stress within the hypertensive liver may induce increased expression of eNOS. In turn, caveolin-1 is also increased. Whether this serves as a defense mechanism against further cirrhosis or is a consequence of cirrhosis, is yet unknown. The elevated expression of HO-1 and HO-2 suggest that CO may compensate in its role as a vasodilator albeit weakly. It is possible that CO and NO have parallel or coordinated functions within the liver and may work antagonistically in the pathophysiology of portal hypertension.
基金Supported by a Grant from the National Basic Research Program of China (973 Program)(No.2006CB504508)
文摘OBJECTIVE： To explore the long-term effects and pain relief mechanism of acupotomy by observing changes in nitric oxide synthase （NOS） and beta-en- dorphin （~3-EP） in the hypothalamus, spinal cord, and peripheral blood of rats with third lumbar ver- tebrae （L3） transverse process syndrome. METHODS： Twenty-eight SD rats were randomly as- signed to normal, model, electroacupuncture （EA）, and acupotomy group. The last three groups were put through an operation to emulate L3 transverse process syndrome. Fourteen days after the simulation operation, EA and acupotomy treatments were applied to the respective groups. Fifty-six days afterthe simulation operation, biochemistry tests and enzyme-linked immunosorbent assay were used to measure NOS and 13-EP in the hypothalamus, spinal cord, and peripheral blood. RESULTS： Rats with the simulation operation showed significantly higher levels of NOS and II3-EP in the hypothalamus, spinal cord, and peripheral blood than those in the normal group. The EA and acupotomy groups had significantly lower levels of NOS and β-EP than those in the model group. There was no statistical difference between the EA and acupotomy groups. CONCLUSION： EA and acupotomy treatments significantly lowered NOS and β-EP levels in the hypothalamus, spinal cord, and peripheral blood and alleviated L3 transverse process syndrome.
文摘AIM: To study the distribution of nitric oxide synthase (NOS) in rat stomach myenteric plexus. METHODS: The distribution of NOS in gastric wall was studied in quantity and location by the NADPH-diaphorase (NDP) histochemical staining method and whole mount preparation technique. RESULTS: NOS was distributed in whole stomach wall, most of them were located in myenteric plexus, and distributed in submucosal plexus.The shape of NOS positive neurons was basically similar, most of them being round and oval in shape. But their density, size and staining intensity varied greatly in the different parts of stomach. The density was 62+/-38 cells mm(2) (antrum), 43+/-32 cells/mm(2) (body), and 32+/-28 cells mm(2) (fundus), respectively. The size and staining intensity of NOS positive neurons in the fundus were basically the same, the neurons being large and dark stained, while they were obviously different in antrum. In the body of the stomach, the NOS positive neurons were in an intermediate state from fundus to antrum. There were some beadlike structures which were strung together by NOS positive varicosities in nerve fibers, some were closely adherent to the outer walls of blood vessels. CONCLUSION: Nitric oxide might be involved in the modulation of motility, secretion and blood circulation of the stomach, and the significant difference of NOS positive neurons in different parts of stomach myenteric plexus may be related to the physiologic function of stomach.
基金Supported by the Scientific Foundation of Jiangsu University,No.2631280055
文摘AIM: To investigate the expression of NOS in gastric carcinoma, and to explore the relationship between the expression of nitric oxide synthases (NOS) and p53, PCNA,pathological features and clinical staging of gastric cancer.METHODS: The activity of NOS protein was investigated in 85 samples of human gastric carcinoma and 25 samples of normal gastric mucosal tissue by biochemical assay. We then examined the expression of NOS, p53, PCNA in 85 samples of human gastric cancer was examined by immunohistochemistry, and NOS mRNA expression in 85 gastric cancer tissue specimens by in situ hybridization.RESULTS: Biochemical assay showed that the activity of NOS was significantly higher in gastric carcinoma than in normal gastric mucosal tissues (t = 0.4161, P＜0.01).Immunohistochemistry revealed that endothelial nitric oxide synthase (eNOS) expressed in all samples of normal gastric mucosa, but only 6 cases of 85 gastric cancer specimens showed weak positive immunohistochemical reactions to eNOS (20%). Inducible nitric oxide synthase (iNOS) was expressed strongly in human gastric carcinoma (81.2%). In situ hybridization analysis showed that iNOS mRNA expression was significantly stronger than eNOS mRNA expression in gastric cancer tissue (x2 = 10.23, P＜0.01). The expression of iNOS in gastric cancer was associated with differentiation, clinical stages or lymph node metastases (r= 0.3426, P＜0.05). However,iNOS expression did not correlate with histological classifications and morphological types. The expression of iNOS was significantly correlated with p53 or PCNA expression (r = 0.3612, P＜0.05). The expression of neuronal nitric oxide synthase (nNOS) was not examined by immunohistochemistry and in situ hybridization in gastric cancer specimens and normal gastric mucosa.CONCLUSION: In human gastric cancer, there is an enhanced expression of iNOS, but not of eNOS. NOS promotes the proliferation of tumor cells and plays an important role in gastric cancer spread. Inactivation of antioncogene p53 and overexpression of iNOS might play a synergetic role in the process of carcinogenesis of human gastric carcinoma.
文摘AIM： TO investigate the dynamic change and role of neuronal nitric oxide synthase （nNOS） and inducible nitric oxide synthase （iNOS） in neonatal rat with intestinal injury and to define whether necrotizing enterocolitis （NEC） is associated with the levels of nitric oxide synthase （NOS） in the mucosa of the affected intestine tissue. METHODS： Wistar rats less than 24 h in age received an intraperitoneal injection with 5 mg/kg lipopolysaccharide （LPS）. Ileum tissues were collected at 1, 3, 6, 12 and 24 h following LPS challenge for histological evaluation of NEC and for measurements of nNOS and iNOS. The correlation between the degree of intestinal injury and levels of NOS was determined. RESULTS： The LPS-injected increase in injury scores pups showed a significant versus the control. The expression of nNOS protein and mRNA was diminished after LPS injection. There was a negative significant correlation between the nNOS protein and the grade of median intestinal injury within 24 h. The expression of iNOS protein and mRNA was significantly increased in the peak of intestinal injury. CONCLUSION： nNOS and iNOS play different roles in LPS-induced intestinal injury. Caution should be exerted concerning potential therapeutic uses of NOS inhibitors in NEC.
基金Project supported by the National Natural Science Foundation of China (No.30771553)National Basic Research Program (973) of China (No.2007CB947403)
文摘Objective: The present study is designed to investigate the cellular expressions and immunolocalizations of three different nitric oxide synthase (NOS) isoforms and the related nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway in the ovaries of neonatal and immature rats.Methods: The ovaries were obtained from ICR (Institute for Cancer Research) female Sprague-Dawley rats at postnatal days 1,5,7,10,and 19.Then we carried out the histologic examination,immunohistochemistry,measurement of NOS activity,and modifications within the NO/cGMP pathway.Results: During postnatal days 1,5,7,10,and 19,all three isoforms of NOS were mainly localized to the oocytes and expressed as a gradual increase in granulosa cells and theca cells within the growing follicle.The ovarian total NOS activities and NO levels were increased at postnatal days 7 and 10 compared with other days.Conclusions: Our findings suggest that the locally produced NO and the NO/NOS signaling systems are involved in the follicular development to puberty.
基金Natural Science Foudation of Hebei ProvinceEducation Department Foundation of Hebei Province.No.2002136.
文摘AIM: To study the distribution of the constitutive nitric oxide synthase (NOS) in the jejunum of adult rat. METHODS: The distribution of endothelial NOS (eNOS) was detected by immunohistochemistry. Immunofluorescence histochemical dual staining technique were used for studying the distribution of neuronal NOS (nNOS) and eNOS. The dual stained slides were observed under a confocal laser scanning microscope. RESULTS: Positive neuronal NOS (nNOS) and endothelial NOS (eNOS) cells were found to be distributed in lamina propria of villi, and the epithelial cell was not stained. eNOS was mainly located in submucosal vascular endothelia, while nNOS was mainly situated in myenteric plexus. Some cells in the villi had both nNOS and eNOS. More than 80% of the cells were positive for both nNOS and eNOS, the rest cells were positive either for nNOS or for eNOS. CONCLUSION: The two constitutive nitric oxide synthases are distributed differently in the jejunum of rat. nNOS distributed in myenteric plexus is a neurotransmitter in the non-adrenergic non-cholinergic (NANC) inhibitory nerves. eNOS distributed in endothelial and smooth muscle cells of blood vessels plays vasodilator role. eNOS and nNOS are coexpressed in some cells of lamina propria of villi. NO generated by those NOS is very important in the physiological and pathological process of small intestine.
文摘In this study, we examined the expression of inducible nitric oxide s ynthase (iNOS) and vascular endothelial growth factor (VEGF) by immunohistoc hemi cal staining in 76 tissue sections collected from hepatocellular carcinoma (HCC) patients undergoing hepatectomy. Microvascular density (MVD) was determined by counting endothelial cells immunostained using anti-CD34 antibody. We performe d DNA-flow cytometric analyses to elucidate the impact of iNOS and VEGF expressi o n on the cell cycle of HCC. Most of the HCC cells that invaded stroma were mark edly immunostained by iNOS antibody. The iNOS stain intensity of the liver tissu e close to the tumor edge was stronger than that of HCC tissue, and the stronges t was the hepatocytes closer to the tumor tissue. However, iNOS expression in 10 normal hepatic samples was undetectable. VEGF positive expression ratio was 84. 8% in iNOS positive expression cases, and the ratio was 35.3% in negative cases. There was significant correlation (P=0.000) between iNOS and VEGF expressi on. Moreover, iNOS expression was significantly associated with bcl-2 and MVD, but w ithout p53 expression. DNA-flow cytometric analyses showed that combined expres s ion of iNOS and VEGF had significant impact on the cell cycle in HCC. PI (Proli ferating Index) and SPF (S-phase fraction) in the combined positive expression o f iNOS and VEGF group was significantly higher than that in the combined negativ e group. The present findings suggested that iNOS expression was significantly a ssociated with angiogenesis, bcl-2 and cell proliferation of HCC.
基金the grant from Natural Foundation of Shaanxi Province, No.2006C240
文摘BACKGROUND： Accumulated evidence indicates an important role for hippocampal dendrite atrophy in development of depression, while brain-derived neurotrophic factor （BDNF） participates in hippocampal dendrite growth. OBJECTIVE： To discuss the role of BDNF and neuronal nitric oxide synthase （nNOS） in chronic and unpredictable stress-induced depression and the pathogenesis of depression. DESIGN, TIME AND SETTING： Randomized, controlled animal experiment. The experiment was carded out from October 2006 to May 2007 at the Department of Animal Physiology, College of Life Science, Shaanxi Normal University. MATERIALS： Thirty-seven male Sprague-Dawley rats weighing 250-300 g at the beginning of the experiment were obtained from Shaanxi Provincial Institute of Traditional Chinese Medicine （Xi＇an, China）. BDNF antibody and nNOS antibody were provided by Santa Cruz （USA）. K252a （BDNF inhibitor） and 7-NI （nNOS inhibitor） were provided by Sigma （USA）. METHODS： Animals were randomly divided into five groups： Control group, chronic unpredicted mild stress （CUMS） group, K252a group, K252a＋7-NI group and 7-NI＋CUMS group. While the Control, K252a and K252a＋7-NI groups of rats not subjected to stress had free access to food and water, other groups of rats were subjected to nine stressors randomly applied for 21 days, with each stressor applied 2-3 times. On days 1, 7, 14 and 21 during CUMS, rats received microinjection of 1 μL of physiological saline in the Control and CUMS groups, 1 ~ L of K252a in the K252a group, 1 μL of K252a and 7-NI in the K252a＋7-NI group, and 1 μL of 7-NI in the 7-NI＋CUMS group. We observed a variety of alterations in sucrose preference, body weight change, open field test and forced swimming test, and observed the expression of BDNF and nNOS in rat hippocampus by immunohistochemistry; MAIN OUTCOME MEASURES： ① A variety.of behavioral alterations of rats; ② The expression of BDNF and nNOS in rat hippocampus. RESULTS： Compared with the Control group, the behavior of the CUMS rats was significantly depressed, the expression of BDNF decreased （P 〈 0.01） but the expression of nNOS increased （P 〈 0.01）. The behavior of rats given intra-hippocampal injection of BDNF inhibitor was significantly depressed and the expression of nNOS was significantly increased （P 〈 0.01）. Intra-hippocampal injections of an nNOS inhibitor reversed the depression-like behavioral changes induced by CUMS or intra-hippocampal injection of BDNF inhibitor. CONCLUSION： CUMS induced a decrease in expression of BDNF and an increase in expression of NO in the hippocampus, which may lead to depression.
