Fenofibrate, an agonist for peroxisome proliferator-activated receptor alpha(PPAR-a), lowers blood pressure, but whether this action is mediated via baroreflex afferents has not been elucidated. In this study, the dis...Fenofibrate, an agonist for peroxisome proliferator-activated receptor alpha(PPAR-a), lowers blood pressure, but whether this action is mediated via baroreflex afferents has not been elucidated. In this study, the distribution of PPAR-a and PPAR-c was assessed in the nodose ganglion(NG) and the nucleus of the solitary tract(NTS). Hypertension induced by drinking high fructose(HFD) was reduced, along with complete restoration of impaired baroreceptor sensitivity, by chronic treatment with fenofibrate. The molecular data also showed that both PPAR-a and PPAR-c were dramatically up-regulated in the NG and NTS of the HFD group. Expression of the downstream signaling molecule of PPAR-a, the mitochondrial uncoupling protein 2(UCP2), was up-regulated in the baroreflex afferent pathway under similar experimental conditions, along with amelioration of reduced superoxide dismutase activity and increased superoxide in HFD rats.These results suggest that chronic treatment with fenofibrate plays a crucial role in the neural control of blood pressure by improving baroreflex afferent function due at least partially to PPAR-mediated up-regulation of UCP2 expression and reduction of oxidative stress.展开更多
Neuropeptide Y (NPY), a metabolism-related cardiovascular factor, plays a crucial role in blood pressure(BP) regulation via peripheral and central pathways. The expression of NPY receptors (Y1R/Y2R) specific to barore...Neuropeptide Y (NPY), a metabolism-related cardiovascular factor, plays a crucial role in blood pressure(BP) regulation via peripheral and central pathways. The expression of NPY receptors (Y1R/Y2R) specific to baroreflex afferents impacts on the sexually dimorphic neural control of circulation. This study was designed to investigate the expression profiles of NPY receptors in the nodose ganglion (NG) and nucleus tractus solitary (NTS) under hypertensive conditions. To this end, rats with hypertension induced by NG-nitro-L-arginine methylester (L-NAME) or high fructose drinking (HFD), and spontaneously hypertensive rats (SHRs) were used to explore the effects/mechanisms of NPY on BP using functional, molecular, and electrophysiological approaches. The data showed that BP was elevated along with baroreceptor sensitivity dysfunction in model rats;Y1R was up-or down-regulated in the NG or NTS of male and female HFD/L-NAME groups,while Y2R was only down-regulated in the HFD groups as well as in the NG of the male L-NAME group. In SHRs,Y1R and Y2R were both down-regulated in the NTS, and not in the NG. In addition to NPY-mediated energy homeostasis, leptin-melanocortin activation may be essential for metabolic disturbance-related hypertension. We found that leptin and a-melanocyte stimulating hormone (aMSH) receptors were aberrantly down-regulated in HFD rats. In addition, a-MSH concentrations were reduced and NPY concentrations were elevated in the serum and NTS at 60 and 90 min after acute leptin infusion. Electrophysiological recordings showed that the decay time-constant and area under the curve of excitatory post-synaptic currents were decreased by Y1R activation in A-types, whereas, both were increased by Y2R activation in Ah-or C-types. These results demonstrate that sex-and afferent-specific NPY receptor expression in the baroreflex afferent pathway is likely to be a novel target for the clinical management of metabolism-related and essential hypertension.展开更多
Excessive reactive oxygen species(ROS)(such as the superoxide radical) are commonly associated with cardiac autonomic dysfunctions. Though superoxide dismutase 1(SOD1) overexpression may protect against ROS damage to ...Excessive reactive oxygen species(ROS)(such as the superoxide radical) are commonly associated with cardiac autonomic dysfunctions. Though superoxide dismutase 1(SOD1) overexpression may protect against ROS damage to the autonomic nervous system, superoxide radical reduction may change normal physiological functions. Previously, we demonstrated that human SOD1(hSOD1) overexpression does not change baroreflex bradycardia and tachycardia but rather increases aortic depressor nerve activity in response to arterial pressure changes in C57 B6 SJL-Tg(SOD1)2 Gur/J mice. Since the baroreflex arc includes afferent, central, and efferent components, the objective of this study was to determine whether hSOD1 overexpression alters the central and vagal efferent mediation of heart rate(HR) responses. Our data indicate that SOD1 overexpression decreased the HR responses to vagal efferent nerve stimulation but did not change the HR responses to aortic depressor nerve(ADN)stimulation. Along with the previous study, we suggest that SOD1 overexpression preserves normal baroreflex function but may differentially alter the functions of the ADN, vagal efferents, and central components. While SOD1 overexpression likely enhanced ADN function and the central mediation of bradycardia, it decreased vagal efferent control of HR.展开更多
Objective: The aim of this study was to assess the relationship of blood pressure variability (BPV) and heart rate variability (HRV) to investigate the effect of baroreflex function on blood pressure variability. Meth...Objective: The aim of this study was to assess the relationship of blood pressure variability (BPV) and heart rate variability (HRV) to investigate the effect of baroreflex function on blood pressure variability. Methods: This study consisted of 111 subjects, including 32 normotensives and 79 hypertensives. All the subjects were given two concurrent tests: 24-hour Holter ECG and ambulatory blood pressure monitoring. According to standard deviation of normal-to-normal sinus RR intervals (SDNN) derived from the Holter ECG, the hypertensives were divided into two groups: an HRV normal group with SDNN > 100 ms and an HRV abnormal group with展开更多
Chronic kidney disease （CKD） patients have high cardiovascular mortality and morbidity. The presence of traditional and CKD related risk factors results in exaggerated vascular calcification in these patients. Vascu...Chronic kidney disease （CKD） patients have high cardiovascular mortality and morbidity. The presence of traditional and CKD related risk factors results in exaggerated vascular calcification in these patients. Vascular calcification is associated with reduced large arterial compliance and thus impaired barorefex sensi-tivity （BRS） resulting in augmented blood pressure （BP） variability and hampered BP regulation. Barorefex plays a vital role in short term regulation of BP. This review discusses the normal barorefex physiology, methods to assess baroreflex function, its determinants along with the prognostic significance of assessing BRS in CKD patients, available literature on BRS in CKD patients and the probable patho-physiology of barorefex dysfunction in CKD.展开更多
Aim Baroreflex dysfunction is associated with a higher rate of sudden death after myocardial infarction （MI）. Ketanserin enhances baroreflex function in rats. The present work was designed to examine whether ketan- ...Aim Baroreflex dysfunction is associated with a higher rate of sudden death after myocardial infarction （MI）. Ketanserin enhances baroreflex function in rats. The present work was designed to examine whether ketan- serin improves the post-MI cardiac function and to explore the possible mechanism involved. Methods Spontane- ously hypertensive rats （SHR） were treated with ketanserin （0.3 mg · kg^-1 · d^-l）. Two weeks later, blood pres- sure and baroreflex function were measured, followed by a ligation of the left coronary artery. The expressions of ve- sicular acetylcholine transporter （VAChT） and α7 nicotinic acetylcholine receptor （α7-nAChR） in ischemic myo- cardium, angiogenesis, cardiac function, and left ventricular （LV） remodeling were evaluated subsequently. Re- sults Ketanserin significantly improved baroreflex sensitivity （0.62 ± 0. 21 vs. 0.34 ± 0. 12 ms/mmHg, P 〈 0.01 ） and vagal tonic activity （ heart rate changes in response to atropine, 54.8 ± 16.2 vs. 37.6 ± 13.4 b. p. m. , P 〈 0.01 ） without affecting the blood pressure or basic heart rate in SHR. Treatment of SHR with ketanserin promi- nently improved cardiac function and alleviated LV remodeling, as reflected by increases in the ejection fraction, fractional shortening, and LV systolic pressure as well as decreases in LV internal diameter and LV relative weight. The capillary density, vascular endothelial growth factor expression, and blood flow in the ischemic myocardium were significantly higher in the ketanserin-treated group. In addition, ketanserin markedly increased the expression of VAChT and α7-nAChR in ischemic myocardium. Conclusion Ketanserin improved post-MI cardiac function and angiogenesis in ischemic myocardium. The findings provide a mechanistic basis for restoring baroreflex function using ketanserin in the treatment of MI.展开更多
OBJECTIVE Microglia M1/M2 po⁃larization play pro-inflammatory and anti-inflam⁃matory roles,respectively,which is involved in memory decline.There is a close relationship between impaired baroreflex function and memory...OBJECTIVE Microglia M1/M2 po⁃larization play pro-inflammatory and anti-inflam⁃matory roles,respectively,which is involved in memory decline.There is a close relationship between impaired baroreflex function and memory impairment.The present study was designed to investigate whether arterial baroreflex deficiency induced by sinoaortic denervation(SAD)affected inflammation through modulation of M1/M2 polar⁃ization leading to the aggravation of learning and memory disorders in rats.METHODS Adult male SD rats were divided into four groups:the sham control,the SAD,the sham+scopolamine,the SAD+scopolamine.In another experiment,there were also four groups:the sham control,the SAD,the SAD+scopolamine and the SAD+scopolamine+ketanserin.All rats were examined for various behaviors using Morris water maze test,new object recognition test,and light dark shuttle test and Y maze test 4 weeks after sham or SAD surgery.CD16,CD206,IL-10,IL-6,IL-1βand TNF-αfrom hippocampus using Western blotting,immunofluorescence and turbidimetry.RESULTS Compared with the sham+scopol⁃amine,the SAD+scopolamine rats showed the reduced crossing times in Morris water maze test,the longer residence time in dark box during light dark shuttle test,and the decreased alterna⁃tion ratio in Y maze test.The level of CD206,IL-10,T-AOC and GSH was decreased,whereas CD16,IL-6,TNF-α,MDA was increased in the hippocampus of SAD+scopolamine rats.Addi⁃tionally,all the above changes were improved in the SAD+scopolamine+ketanserin rats when compared with the SAD+scopolamine.CONCLU⁃SION Arterial baroreflex dysfunction aggravates learning and memory disorders in rats,which may be related to the polarization of microglia.展开更多
OBJECTIVE Platelets play a major role in mediating inflammatory response.The present work was designed to investigate whether arterial baroreflex impairment induced by sinoaortic denervation(SAD)affect platelet activa...OBJECTIVE Platelets play a major role in mediating inflammatory response.The present work was designed to investigate whether arterial baroreflex impairment induced by sinoaortic denervation(SAD)affect platelet activation,leading to the exacerbation of cerebral cortex and hippocampus inflammation in rats.METHODS Adult male SD rats were divided into four groups:the sham control,the sinoaortic denervation(SAD),the sham+LPS,the SAD+LPS.In another experiment,there were also four groups:the sham control,the SAD,the SAD+LPS and the SAD+LPS+asprin.Four weeks after sham or SAD surgery,all rats were examined for the level of CD41,CD45,IL-1βand PF-4 in the cerebral cortex and hippocampus using immunofluorescence and ELISA.Blood platelet and leukocyte count,platelet microaggre⁃gation,expression of CD154 and CD62P on platelet surface and platelet-leukocyte aggregate level was detected by flow cytometry.RESULTS Compared with sham+LPS group,the in SAD+LPS group rats exhibited the high level of CD41,CD45,IL-1βand PF-4 in the cerebral cortex and hippocampus.Leukocyte count,platelet microag⁃gregation,expression of CD154 and CD62P on platelet surface and platelet-leukocyte aggregate level was increased,while blood platelet count was decreased in the SAD+LPS.Moreover,all the above changes were improved in the SAD+LPS+asprin group when compared with the SAD+LPS group.CONCLUSION Arterial baroreflex dysfunction exacerbates inflammation in the rat cerebral cortex and hippocampus,which is likely mediated by platelet.展开更多
Purpose: African-American men (AAM) have a greater risk of hypertension (HTN) than Caucasian men (CM). To reduce this risk, determining the differences in mechanisms involved in HTN and understanding the relationship ...Purpose: African-American men (AAM) have a greater risk of hypertension (HTN) than Caucasian men (CM). To reduce this risk, determining the differences in mechanisms involved in HTN and understanding the relationship between these mechanisms and factors affecting blood pressure (BP) in AAM and CM is necessary. One such mechanism is spontaneous baroreflex sensitivity (sBRS) and two factors are cardiorespiratory fitness (CRF) and arterial stiffness (AS). The aims of this study were to determine, firstly, whether there are differences in sBRS between young, normotensive AAM and CM, and secondly, to determine if CRF and AS are significant predictors of sBRS in young, normotensive AAM and CM. Methods: Twenty-three normotensive AAM and 36 CM were recruited from Southern Connecticut State University. Measures included anthropometric, sBRS (alpha-index), and CRF (maximal oxygen consumption [VO2max]), as well as AS (carotid-femoral pulse wave velocity [Cf-PWV]). Independent t-tests were used to determine differences between groups and multiple regression analysis was used to determine how much of the variation in sBRS was explained by CRF and AS. Results: The sBRS was significantly lower in AAM (10.3 ± 3.8 ms/mmHg) vs. CM (13.3 ± 5.7 ms/ mmHg), P = 0.03. CRF and AS were not significant predictors of sBRS in AAM (P = 0.25) and CM (P = 0.30). There was no relationship between, sBRS, CRF and AS;CRF was significantly reduced in AAM vs. CM (45.1 ± 6.3 vs. 52.1 ± 7.5 mL·kg?1·min?1, P ≤ 0.001). Conclusions: Young normotensive AAM demonstrated significantly lower sBRS vs. CM, irrespective of having fair CRF and normal BP. CRF and AS are not significant predictors of sBRS in young, normotensive AAM and CM. The attenuation in sBRS in AAM did not result in AAM having higher BP versus CM. This finding underscores the need for more detailed examination of the role of sBRS in the etiology of HTN in AAM.展开更多
Continuous treatment with organic nitrates causes nitrate tolerance and provides evidence for a relationship between mitochondrial complex 1 activity and mitochondrial aldehyde dehydrogenase-2 (ALDH-2) with disturbanc...Continuous treatment with organic nitrates causes nitrate tolerance and provides evidence for a relationship between mitochondrial complex 1 activity and mitochondrial aldehyde dehydrogenase-2 (ALDH-2) with disturbances of the hemodynamics reaction during nitroglycerin (NTG) tolerance (NTGT). The purpose of this study was the evaluation of efficacy of original oxidized form NAD-containing drug, NADCIN<sup>®</sup>, on hemodynamic reactions, baroreflex sensitivity (BRS) and reflex control of splanchnic sympathetic nerve activity (SSNA), level of redox-potential, activity of ALDH-2 and superoxide anion generation in aortic tissue in rat model of NTGT. Five groups (7 - 9 each) of male Wistar rats, including control, acute i.v. NTG (150 mcg/kg) administration, NTG tolerance NTGT treatment with NADCIN<sup>®</sup> 8 mg/kg and methylene blue (MB, 2.5 mg/kg) were used. NTGT in rats was accompanied with the greatly attenuation of hemodynamics reaction, BRS, the decreasing of the ability to reflex control of SSNA without pronounce overexpression of endothelin-1 in vessels (aorta). In NTGT rats i.v. NTG along induced less hypotensive reactions and alterations in heart period vs single NTG treated group, more expressively decreased BRS (-34%) and reflex control of SSNA (-18%). NADCIN<sup>®</sup> significantly inhibits tolerance-inducing properties of the prolonged nitroglycerin infusion (max decrease of blood pressure response to nitroglycerin injection, % of normal controls: NTGT 51.2%, NADCIN<sup>®</sup> 91.6%, MB 55.8%). NADCIN<sup>®</sup> in NTGT rats after NTG i.v. administration increased reduced BRS (+37.8%, p < 0,05), reflex control of SSNA (+29.4%, p < 0.05) and reversed the decreasing of NAD/NADH ratio, ALDH-2 activity and decreasing in superoxide generation in thoracic aortic tissue. Thus, course treatment with NADCIN<sup>®</sup> of NTGT rats restores hemodynamics changes, BRS and SSNA throughout the increasing of redox-potential NAD/NADH and cessates the NTGT developing.展开更多
Objective To study thechanges of baroreflex sensitivity (BRS) during head - up tilt test (HUT) in patients with vasovagal syncope (VS), and to examine the relationship between baroreflex sensitivity and neurohormonal ...Objective To study thechanges of baroreflex sensitivity (BRS) during head - up tilt test (HUT) in patients with vasovagal syncope (VS), and to examine the relationship between baroreflex sensitivity and neurohormonal factors. Furthermore, to investigate the effects of the changes of BRS on VS. Methods Forty - two patients with unexplained syncope (Among the 42 patients, there were 22 patients with positive HUT and 20 patients with negative HUT respectively) and 20 healthy volunteers (with negative HUT) underwent passive head - up tilt testing, Ante-cubital vein blood samples were taken before and after HUT, or at syncope. The fasting plasma endothelin , serum nitric oxide (NO), serum NE were measured, the BRS was assessed on the basis of the linear regression slope the RR interval versus systolic arterial blood pressure during the increment in blood pressure after intravenous administration of phenylephrine. Results (1) During the syncope, the BRS significantly reduced in HUT(+) group than baseline. At the end of tilt, the level of plasma ET, serum NO in patients with positive HUT significantly increased compared with baseline or normal controls, and the plasma concentration of NE also had the trend of increase. (2) By multiple regression analysis, a significant negative correlation was found between baroreceptor sensitivity and the plasma ET, NO at the end of HUT in patients with positive HUT, but there was no relationship between BRS and NE. Conclusions During the syncope occure, the BRS in patients with VS decreased significantly compared with normal controls. The abnormal plasma ET, NO concen-tration might contribute to the mechanism of VS.展开更多
基金supported by the National Natural Science Foundation of China(81573431 and 81773731)
文摘Fenofibrate, an agonist for peroxisome proliferator-activated receptor alpha(PPAR-a), lowers blood pressure, but whether this action is mediated via baroreflex afferents has not been elucidated. In this study, the distribution of PPAR-a and PPAR-c was assessed in the nodose ganglion(NG) and the nucleus of the solitary tract(NTS). Hypertension induced by drinking high fructose(HFD) was reduced, along with complete restoration of impaired baroreceptor sensitivity, by chronic treatment with fenofibrate. The molecular data also showed that both PPAR-a and PPAR-c were dramatically up-regulated in the NG and NTS of the HFD group. Expression of the downstream signaling molecule of PPAR-a, the mitochondrial uncoupling protein 2(UCP2), was up-regulated in the baroreflex afferent pathway under similar experimental conditions, along with amelioration of reduced superoxide dismutase activity and increased superoxide in HFD rats.These results suggest that chronic treatment with fenofibrate plays a crucial role in the neural control of blood pressure by improving baroreflex afferent function due at least partially to PPAR-mediated up-regulation of UCP2 expression and reduction of oxidative stress.
基金grants from the National Natural Science Foundation of China(31171122,81573431,81773731,81971326,and 8190130222).
文摘Neuropeptide Y (NPY), a metabolism-related cardiovascular factor, plays a crucial role in blood pressure(BP) regulation via peripheral and central pathways. The expression of NPY receptors (Y1R/Y2R) specific to baroreflex afferents impacts on the sexually dimorphic neural control of circulation. This study was designed to investigate the expression profiles of NPY receptors in the nodose ganglion (NG) and nucleus tractus solitary (NTS) under hypertensive conditions. To this end, rats with hypertension induced by NG-nitro-L-arginine methylester (L-NAME) or high fructose drinking (HFD), and spontaneously hypertensive rats (SHRs) were used to explore the effects/mechanisms of NPY on BP using functional, molecular, and electrophysiological approaches. The data showed that BP was elevated along with baroreceptor sensitivity dysfunction in model rats;Y1R was up-or down-regulated in the NG or NTS of male and female HFD/L-NAME groups,while Y2R was only down-regulated in the HFD groups as well as in the NG of the male L-NAME group. In SHRs,Y1R and Y2R were both down-regulated in the NTS, and not in the NG. In addition to NPY-mediated energy homeostasis, leptin-melanocortin activation may be essential for metabolic disturbance-related hypertension. We found that leptin and a-melanocyte stimulating hormone (aMSH) receptors were aberrantly down-regulated in HFD rats. In addition, a-MSH concentrations were reduced and NPY concentrations were elevated in the serum and NTS at 60 and 90 min after acute leptin infusion. Electrophysiological recordings showed that the decay time-constant and area under the curve of excitatory post-synaptic currents were decreased by Y1R activation in A-types, whereas, both were increased by Y2R activation in Ah-or C-types. These results demonstrate that sex-and afferent-specific NPY receptor expression in the baroreflex afferent pathway is likely to be a novel target for the clinical management of metabolism-related and essential hypertension.
基金supported by National Institutes of Health grant HL-75034by Institutional Funds of the University of Central Florida
文摘Excessive reactive oxygen species(ROS)(such as the superoxide radical) are commonly associated with cardiac autonomic dysfunctions. Though superoxide dismutase 1(SOD1) overexpression may protect against ROS damage to the autonomic nervous system, superoxide radical reduction may change normal physiological functions. Previously, we demonstrated that human SOD1(hSOD1) overexpression does not change baroreflex bradycardia and tachycardia but rather increases aortic depressor nerve activity in response to arterial pressure changes in C57 B6 SJL-Tg(SOD1)2 Gur/J mice. Since the baroreflex arc includes afferent, central, and efferent components, the objective of this study was to determine whether hSOD1 overexpression alters the central and vagal efferent mediation of heart rate(HR) responses. Our data indicate that SOD1 overexpression decreased the HR responses to vagal efferent nerve stimulation but did not change the HR responses to aortic depressor nerve(ADN)stimulation. Along with the previous study, we suggest that SOD1 overexpression preserves normal baroreflex function but may differentially alter the functions of the ADN, vagal efferents, and central components. While SOD1 overexpression likely enhanced ADN function and the central mediation of bradycardia, it decreased vagal efferent control of HR.
文摘Objective: The aim of this study was to assess the relationship of blood pressure variability (BPV) and heart rate variability (HRV) to investigate the effect of baroreflex function on blood pressure variability. Methods: This study consisted of 111 subjects, including 32 normotensives and 79 hypertensives. All the subjects were given two concurrent tests: 24-hour Holter ECG and ambulatory blood pressure monitoring. According to standard deviation of normal-to-normal sinus RR intervals (SDNN) derived from the Holter ECG, the hypertensives were divided into two groups: an HRV normal group with SDNN > 100 ms and an HRV abnormal group with
文摘Chronic kidney disease （CKD） patients have high cardiovascular mortality and morbidity. The presence of traditional and CKD related risk factors results in exaggerated vascular calcification in these patients. Vascular calcification is associated with reduced large arterial compliance and thus impaired barorefex sensi-tivity （BRS） resulting in augmented blood pressure （BP） variability and hampered BP regulation. Barorefex plays a vital role in short term regulation of BP. This review discusses the normal barorefex physiology, methods to assess baroreflex function, its determinants along with the prognostic significance of assessing BRS in CKD patients, available literature on BRS in CKD patients and the probable patho-physiology of barorefex dysfunction in CKD.
文摘Aim Baroreflex dysfunction is associated with a higher rate of sudden death after myocardial infarction （MI）. Ketanserin enhances baroreflex function in rats. The present work was designed to examine whether ketan- serin improves the post-MI cardiac function and to explore the possible mechanism involved. Methods Spontane- ously hypertensive rats （SHR） were treated with ketanserin （0.3 mg · kg^-1 · d^-l）. Two weeks later, blood pres- sure and baroreflex function were measured, followed by a ligation of the left coronary artery. The expressions of ve- sicular acetylcholine transporter （VAChT） and α7 nicotinic acetylcholine receptor （α7-nAChR） in ischemic myo- cardium, angiogenesis, cardiac function, and left ventricular （LV） remodeling were evaluated subsequently. Re- sults Ketanserin significantly improved baroreflex sensitivity （0.62 ± 0. 21 vs. 0.34 ± 0. 12 ms/mmHg, P 〈 0.01 ） and vagal tonic activity （ heart rate changes in response to atropine, 54.8 ± 16.2 vs. 37.6 ± 13.4 b. p. m. , P 〈 0.01 ） without affecting the blood pressure or basic heart rate in SHR. Treatment of SHR with ketanserin promi- nently improved cardiac function and alleviated LV remodeling, as reflected by increases in the ejection fraction, fractional shortening, and LV systolic pressure as well as decreases in LV internal diameter and LV relative weight. The capillary density, vascular endothelial growth factor expression, and blood flow in the ischemic myocardium were significantly higher in the ketanserin-treated group. In addition, ketanserin markedly increased the expression of VAChT and α7-nAChR in ischemic myocardium. Conclusion Ketanserin improved post-MI cardiac function and angiogenesis in ischemic myocardium. The findings provide a mechanistic basis for restoring baroreflex function using ketanserin in the treatment of MI.
基金Natural Science Foundation of Shandong Province(ZR2017MH048)。
文摘OBJECTIVE Microglia M1/M2 po⁃larization play pro-inflammatory and anti-inflam⁃matory roles,respectively,which is involved in memory decline.There is a close relationship between impaired baroreflex function and memory impairment.The present study was designed to investigate whether arterial baroreflex deficiency induced by sinoaortic denervation(SAD)affected inflammation through modulation of M1/M2 polar⁃ization leading to the aggravation of learning and memory disorders in rats.METHODS Adult male SD rats were divided into four groups:the sham control,the SAD,the sham+scopolamine,the SAD+scopolamine.In another experiment,there were also four groups:the sham control,the SAD,the SAD+scopolamine and the SAD+scopolamine+ketanserin.All rats were examined for various behaviors using Morris water maze test,new object recognition test,and light dark shuttle test and Y maze test 4 weeks after sham or SAD surgery.CD16,CD206,IL-10,IL-6,IL-1βand TNF-αfrom hippocampus using Western blotting,immunofluorescence and turbidimetry.RESULTS Compared with the sham+scopol⁃amine,the SAD+scopolamine rats showed the reduced crossing times in Morris water maze test,the longer residence time in dark box during light dark shuttle test,and the decreased alterna⁃tion ratio in Y maze test.The level of CD206,IL-10,T-AOC and GSH was decreased,whereas CD16,IL-6,TNF-α,MDA was increased in the hippocampus of SAD+scopolamine rats.Addi⁃tionally,all the above changes were improved in the SAD+scopolamine+ketanserin rats when compared with the SAD+scopolamine.CONCLU⁃SION Arterial baroreflex dysfunction aggravates learning and memory disorders in rats,which may be related to the polarization of microglia.
基金Natural Science Foundation of Shandong Province(ZR2017MH048)。
文摘OBJECTIVE Platelets play a major role in mediating inflammatory response.The present work was designed to investigate whether arterial baroreflex impairment induced by sinoaortic denervation(SAD)affect platelet activation,leading to the exacerbation of cerebral cortex and hippocampus inflammation in rats.METHODS Adult male SD rats were divided into four groups:the sham control,the sinoaortic denervation(SAD),the sham+LPS,the SAD+LPS.In another experiment,there were also four groups:the sham control,the SAD,the SAD+LPS and the SAD+LPS+asprin.Four weeks after sham or SAD surgery,all rats were examined for the level of CD41,CD45,IL-1βand PF-4 in the cerebral cortex and hippocampus using immunofluorescence and ELISA.Blood platelet and leukocyte count,platelet microaggre⁃gation,expression of CD154 and CD62P on platelet surface and platelet-leukocyte aggregate level was detected by flow cytometry.RESULTS Compared with sham+LPS group,the in SAD+LPS group rats exhibited the high level of CD41,CD45,IL-1βand PF-4 in the cerebral cortex and hippocampus.Leukocyte count,platelet microag⁃gregation,expression of CD154 and CD62P on platelet surface and platelet-leukocyte aggregate level was increased,while blood platelet count was decreased in the SAD+LPS.Moreover,all the above changes were improved in the SAD+LPS+asprin group when compared with the SAD+LPS group.CONCLUSION Arterial baroreflex dysfunction exacerbates inflammation in the rat cerebral cortex and hippocampus,which is likely mediated by platelet.
文摘Purpose: African-American men (AAM) have a greater risk of hypertension (HTN) than Caucasian men (CM). To reduce this risk, determining the differences in mechanisms involved in HTN and understanding the relationship between these mechanisms and factors affecting blood pressure (BP) in AAM and CM is necessary. One such mechanism is spontaneous baroreflex sensitivity (sBRS) and two factors are cardiorespiratory fitness (CRF) and arterial stiffness (AS). The aims of this study were to determine, firstly, whether there are differences in sBRS between young, normotensive AAM and CM, and secondly, to determine if CRF and AS are significant predictors of sBRS in young, normotensive AAM and CM. Methods: Twenty-three normotensive AAM and 36 CM were recruited from Southern Connecticut State University. Measures included anthropometric, sBRS (alpha-index), and CRF (maximal oxygen consumption [VO2max]), as well as AS (carotid-femoral pulse wave velocity [Cf-PWV]). Independent t-tests were used to determine differences between groups and multiple regression analysis was used to determine how much of the variation in sBRS was explained by CRF and AS. Results: The sBRS was significantly lower in AAM (10.3 ± 3.8 ms/mmHg) vs. CM (13.3 ± 5.7 ms/ mmHg), P = 0.03. CRF and AS were not significant predictors of sBRS in AAM (P = 0.25) and CM (P = 0.30). There was no relationship between, sBRS, CRF and AS;CRF was significantly reduced in AAM vs. CM (45.1 ± 6.3 vs. 52.1 ± 7.5 mL·kg?1·min?1, P ≤ 0.001). Conclusions: Young normotensive AAM demonstrated significantly lower sBRS vs. CM, irrespective of having fair CRF and normal BP. CRF and AS are not significant predictors of sBRS in young, normotensive AAM and CM. The attenuation in sBRS in AAM did not result in AAM having higher BP versus CM. This finding underscores the need for more detailed examination of the role of sBRS in the etiology of HTN in AAM.
文摘Continuous treatment with organic nitrates causes nitrate tolerance and provides evidence for a relationship between mitochondrial complex 1 activity and mitochondrial aldehyde dehydrogenase-2 (ALDH-2) with disturbances of the hemodynamics reaction during nitroglycerin (NTG) tolerance (NTGT). The purpose of this study was the evaluation of efficacy of original oxidized form NAD-containing drug, NADCIN<sup>®</sup>, on hemodynamic reactions, baroreflex sensitivity (BRS) and reflex control of splanchnic sympathetic nerve activity (SSNA), level of redox-potential, activity of ALDH-2 and superoxide anion generation in aortic tissue in rat model of NTGT. Five groups (7 - 9 each) of male Wistar rats, including control, acute i.v. NTG (150 mcg/kg) administration, NTG tolerance NTGT treatment with NADCIN<sup>®</sup> 8 mg/kg and methylene blue (MB, 2.5 mg/kg) were used. NTGT in rats was accompanied with the greatly attenuation of hemodynamics reaction, BRS, the decreasing of the ability to reflex control of SSNA without pronounce overexpression of endothelin-1 in vessels (aorta). In NTGT rats i.v. NTG along induced less hypotensive reactions and alterations in heart period vs single NTG treated group, more expressively decreased BRS (-34%) and reflex control of SSNA (-18%). NADCIN<sup>®</sup> significantly inhibits tolerance-inducing properties of the prolonged nitroglycerin infusion (max decrease of blood pressure response to nitroglycerin injection, % of normal controls: NTGT 51.2%, NADCIN<sup>®</sup> 91.6%, MB 55.8%). NADCIN<sup>®</sup> in NTGT rats after NTG i.v. administration increased reduced BRS (+37.8%, p < 0,05), reflex control of SSNA (+29.4%, p < 0.05) and reversed the decreasing of NAD/NADH ratio, ALDH-2 activity and decreasing in superoxide generation in thoracic aortic tissue. Thus, course treatment with NADCIN<sup>®</sup> of NTGT rats restores hemodynamics changes, BRS and SSNA throughout the increasing of redox-potential NAD/NADH and cessates the NTGT developing.
文摘Objective To study thechanges of baroreflex sensitivity (BRS) during head - up tilt test (HUT) in patients with vasovagal syncope (VS), and to examine the relationship between baroreflex sensitivity and neurohormonal factors. Furthermore, to investigate the effects of the changes of BRS on VS. Methods Forty - two patients with unexplained syncope (Among the 42 patients, there were 22 patients with positive HUT and 20 patients with negative HUT respectively) and 20 healthy volunteers (with negative HUT) underwent passive head - up tilt testing, Ante-cubital vein blood samples were taken before and after HUT, or at syncope. The fasting plasma endothelin , serum nitric oxide (NO), serum NE were measured, the BRS was assessed on the basis of the linear regression slope the RR interval versus systolic arterial blood pressure during the increment in blood pressure after intravenous administration of phenylephrine. Results (1) During the syncope, the BRS significantly reduced in HUT(+) group than baseline. At the end of tilt, the level of plasma ET, serum NO in patients with positive HUT significantly increased compared with baseline or normal controls, and the plasma concentration of NE also had the trend of increase. (2) By multiple regression analysis, a significant negative correlation was found between baroreceptor sensitivity and the plasma ET, NO at the end of HUT in patients with positive HUT, but there was no relationship between BRS and NE. Conclusions During the syncope occure, the BRS in patients with VS decreased significantly compared with normal controls. The abnormal plasma ET, NO concen-tration might contribute to the mechanism of VS.
