BACKGROUND Myocardial infarction is a high-risk condition prevalent among the elderly population,often leading to adverse clinical manifestations such as reduced cardiopulmonary function,anxiety,and depression post-su...BACKGROUND Myocardial infarction is a high-risk condition prevalent among the elderly population,often leading to adverse clinical manifestations such as reduced cardiopulmonary function,anxiety,and depression post-surgery.Consequently,cardiac rehabilitation holds immense importance in mitigating these complications.AIM To evaluate the effect of individualized cardiac rehabilitation on blood pressure variability(BPV)and baroreflex sensitivity(BRS)in elderly patients with myocardial infarction.METHODS A cohort of 74 elderly patients diagnosed with myocardial infarction and admitted to our hospital between January 2021 and January 2022 were subjected to random selection.Subsequently,all patients were divided into two groups,namely the research group(n=37)and the control group(n=37),utilizing the number table method.The control group received conventional drug treatment and nursing guidance intervention,while the study group underwent individualized cardiac rehabilitation in addition to the interventions received by the control group.All patients were continuously intervened for 12 wk,and the BPV of these two groups in the 1st wk(T0),the 4th wk(T1)and the 12th wk(T2)were compared,BRS,changes in cardiopulmonary function measures,and adverse cardiovascular events.RESULTS Of 24 h diastolic BPV,24 h systolic BPV,carbon dioxide ventilation equivalent slope of the research group were lower than those of the control group at T1 and T2,BRS,peak heart rate and systolic blood pressure product,1 min heart rate recovery were higher than those of the control group,and the incidence of adverse events in the research group was lower than that of the control group,the difference was statistically significant(P<0.05).CONCLUSION In this study,we found that after individualized cardiac rehabilitation in elderly patients with myocardial infarction,BPV and BRS can be effectively improved,cardiac function is significantly enhanced,and a better prognosis is obtained.展开更多
Human cardiovascular system(CVS)and hemodynamics are critically sensitive to essential alterations of mechanical inertial forces in directions of head-legs(+Gz)or legs-head(-Gz).Typically,such alterations appear durin...Human cardiovascular system(CVS)and hemodynamics are critically sensitive to essential alterations of mechanical inertial forces in directions of head-legs(+Gz)or legs-head(-Gz).Typically,such alterations appear during pilotage maneuvers of modern high maneuverable airspace vehicles(HMAV).The vulnerability of pilots or passengers of HMAV to these altering forces depends on their three main characteristics:amplitude,dynamics,and duration.Special protections,proposed to minimize this vulnerability,should be improved in parallel with the increasing of these hazardous characteristics of HMAVs.Empiric testing of novel protection methods and tools is both expensive and hazardous.Therefore computer simulations are encouraged.Autonomic software(AS)for simulating and theoretical investigating of the main dynamic responses of human CVS to altering Gz is developed.AS is based on a system of quantitative mathematical models(QMM)consisting of about 1300 differential and algebraic equations.QMM describes the dynamics of both CVS(the cardiac pump function,baroreceptor control of parameters of cardiovascular net presented by means of lumped parameter vascular compartments)and non-biological variables(inertial forces,and used protections).The main function of AS is to provide physiologist-researcher by visualizations of calculated additional data concerning characteristics of both external and internal environments under high sustained accelerations and short-time microgravity.Additionally,AS can be useful as an educational tool able to show both researchers and young pilots the main hemodynamic effects caused by accelerations and acute weightlessness with and without use of different protection tools and technics.In this case,AS does help users to optimize training process aimed to ensure optimal-like human tolerance to the altered physical environment.Main physiological events appearing under different scenarios of accelerations and microgravity have been tested.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
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
Clinical trials and animal experimental studies have demonstrated an association of arterial baroreflex impairment with the prognosis and mortality of cardiovascular diseases and diabetes. As a primary part of the art...Clinical trials and animal experimental studies have demonstrated an association of arterial baroreflex impairment with the prognosis and mortality of cardiovascular diseases and diabetes. As a primary part of the arterial baroreflex arc, the pressure sensitivity of arterial baroreceptors is blunted and involved in arterial baroreflex dysfunction in cardiovascular diseases and diabetes.Changes in the arterial vascular walls, mechanosensitive ion channels, and voltage-gated ion channels contribute to the attenuation of arterial baroreceptor sensitivity. Some endogenous substances(such as angiotensin II and superoxide anion) can modulate these morphological and functional alterations through intracellular signaling pathways in impaired arterial baroreceptors. Arterial baroreceptors can be considered as a potential therapeutic target to improve the prognosis of patients with cardiovascular diseases and diabetes.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
Baroreflex plays a significant role in modulating blood pressure for the human body.It is known that activation of the vagal nerve related to baroreflex can lead to reductions of blood pressure.However,how the vagal a...Baroreflex plays a significant role in modulating blood pressure for the human body.It is known that activation of the vagal nerve related to baroreflex can lead to reductions of blood pressure.However,how the vagal activities quantitatively relate with blood pressure can hardly be achieved.Here fine carbon nanotube yarn(CNTy)electrodes were adopted for recording intrafascicular vagal activities,synchronized with measurement of arterial blood pressure in a rat.Together with a novel algorithm,the results preliminarily quantified that there were six clusters of neural spikes within recorded vagal activities,and the number of individual vagal spikes correspondingly varied with blood pressure.Especially for Cluster 2,the neural activations decreased with arterial blood pressure increasing.This study can shed lights on the quantified neural mechanism underlying the control of vagal activities on blood pressure,and guide the vagal-nerve neuromodulation for treating hypertension.展开更多
Background:Military-related post-traumatic stress(PTS)is associated with numerous symptom clusters and diminished autonomic cardiovascular regulation.Highresolution,relational,resonance-based,electroencephalic mirrori...Background:Military-related post-traumatic stress(PTS)is associated with numerous symptom clusters and diminished autonomic cardiovascular regulation.Highresolution,relational,resonance-based,electroencephalic mirroringis a noninvasive,closed-loop,allostatic,acoustic stimulation neurotechnology that produces realtime translation of dominant brain frequencies into audible tones of variable pitch and timing to support the autocalibration of neural oscillations.We report clinical,autonomic,and functional effects after the use offor symptoms of military-related PTS.Methods:Eighteen service members or recent veterans(15 active-duty,3 veterans,most from special operations,1 female),with a mean age of 40.9(SD=6.9)years and symptoms of PTS lasting from 1 to 25 years,undertook19.5(SD=1.1)sessions over 12 days.Inventories for symptoms of PTS(Posttraumatic Stress Disorder Checklist–Military version,PCL-M),insomnia(Insomnia Severity Index,ISI),depression(Center for Epidemiologic Studies Depression Scale,CES-D),and anxiety(Generalized Anxiety Disorder 7-item scale,GAD-7)were collected before(Visit1,V1),immediately after(Visit2,V2),and at 1 month(Visit3,V3),3(Visit4,V4),and 6(Visit5,V5)months after intervention completion.Other measures only taken at V1 and V2 included blood pressure and heart rate recordings to analyze heart rate variability(HRV)and baroreflex sensitivity(BRS),functional performance(reaction and grip strength)testing,blood and saliva for biomarkers of stress and inflammation,and blood for epigenetic testing.Paired t-tests,Wilcoxon signed-rank tests,and a repeated-measures ANOVA were performed.Results:Clinically relevant,significant reductions in all symptom scores were observed at V2,with durability through V5.There were significant improvements in multiple measures of HRV and BRS[Standard deviation of the normal beat to normal beat interval(SDNN),root mean square of the successive differences(rMSSD),high frequency(HF),low frequency(LF),and total power,HF alpha,sequence all,and systolic,diastolic and mean arterial pressure]as well as reaction testing.Trends were seen for improved grip strength and a reduction in C-Reactive Protein(CRP),Angiotensin II to Angiotensin 1–7 ratio and Interleukin-10,with no change in DNA n-methylation.There were no dropouts or adverse events reported. Conclusion:Service members or veterans showed reductions in symptomatology of PTS,insomnia,depressive mood,and anxiety that were durable through 6 months after the use of a closed-loop allostatic neurotechnology for the autocalibration of neural oscillations.This study is the first to report increased HRV or BRS after the use of an intervention for service members or veterans with PTS.Ongoing investigations are strongly warranted.Trial registration:NCT03230890,retrospectively registered July 25,2017.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
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
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
Despite repeated attempts to develop a unifying hypothesis that explains the clinical syndrome of heart failure(HF),no single conceptual paradigm for HF has withstood the test of time. The last model that has been dev...Despite repeated attempts to develop a unifying hypothesis that explains the clinical syndrome of heart failure(HF),no single conceptual paradigm for HF has withstood the test of time. The last model that has been developed,the neurohormonal model,has the great virtue of highlighting the role of the heart as an endocrine organ,as well as to shed some light on the key role on HF progression of neurohormones and peripheral organs and tissues beyond the heart itself. However,while survival in clinical trials based on neurohormonal antagonist drugs has improved,HF currently remains a lethal condition. At the borders of the neurohormonal model of HF,a partially unexplored path trough the maze of HF pathophysiology is represented by the feedback systems. There are several evidences,from both animal studies and humans reports,that the deregulation of baro-,ergo- and chemo-reflexes in HF patients elicits autonomic imbalance associated with parasympathetic withdrawal and increased adrenergic drive to the heart,thus fundamentally contributing to the evolution of the disease. Hence,on top of guidelinerecommended medical therapy,mainly based on neurohormonal antagonisms,all visceral feedbacks have been recently considered in HF patients as additional potential therapeutic targets.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
The brainstem is a major site in the central nervous system involved in the processing of the cardiovascular reflexes such as the baroreflex and the peripheral chemoreflex. The nucleus tractus solitarius and the rostr...The brainstem is a major site in the central nervous system involved in the processing of the cardiovascular reflexes such as the baroreflex and the peripheral chemoreflex. The nucleus tractus solitarius and the rostral ventrolateral medulla are 2 important brainstem nuclei, and they play pivotal roles in autonomic cardiovascular regulation. Angiotensin II is one of the neurotransmitters involved in the processing of the known that one of the mechanisms by which angiotensin II exerts cardiovascular reflexes within the brainstem. It is well- its effect is via the activation of pathways that generate reactive oxygen species （ROS）. In the central nervous system, ROS are reported to be involved in several pathological dis- eases such as hypertension, heart failure and sleep apnea. However, little is known about the role of ROS in the processing of the cardiovascular reflexes within the brainstem. The present review mainly discussed some recent findings documenting a role for ROS in the processing of the baroreflex and the peripheral chemoreflex in the brainstem.展开更多
Objective: To introduce a method to calculate cardiovascular age, a new, accurate and much simpler index for assessing cardiovascular autonomic regulatory function, based on statistical analysis of heart rate and bloo...Objective: To introduce a method to calculate cardiovascular age, a new, accurate and much simpler index for assessing cardiovascular autonomic regulatory function, based on statistical analysis of heart rate and blood pressure variability (HRV and BPV) and baroreflex sensitivity (BRS) data. Methods: Firstly, HRV and BPV of 89 healthy aviation personnel were analyzed by the conventional autoregressive (AR) spectral analysis and their spontaneous BRS was obtained by the sequence method. Secondly, principal component analysis was conducted over original and derived indices of HRV, BPV and BRS data and the relevant principal components, PCi orig and PCi deri (i=1, 2, 3,...) were obtained. Finally, the equation for calculating cardiovascular age was obtained by multiple regression with the chronological age being assigned as the dependent variable and the principal components significantly related to age as the regressors. Results: The first four principal components of original indices accounted for over 90% of total variance of the indices, so did the first three principal components of derived indices. So, these seven principal components could reflect the information of cardiovascular autonomic regulation which was embodied in the 17 indices of HRV, BPV and BRS exactly with a minimal loss of information. Of the seven principal components, PC2 orig , PC4 orig and PC2 deri were negatively correlated with the chronological age ( P <0 05), whereas the PC3 orig was positively correlated with the chronological age ( P <0 01). The cardiovascular age thus calculated from the regression equation was significantly correlated with the chronological age among the 89 aviation personnel ( r =0.73, P <0 01). Conclusion: The cardiovascular age calculated based on a multi variate analysis of HRV, BPV and BRS could be regarded as a comprehensive indicator reflecting the age dependency of autonomic regulation of cardiovascular system in healthy aviation personnel.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:Oncocardiology is increasingly hot research field/topic in the clinical management of cancer with anti-angiogenic therapy of vascular endothelial growth factor(VEGF)that may cause cardiovascular toxicity,suc...Objective:Oncocardiology is increasingly hot research field/topic in the clinical management of cancer with anti-angiogenic therapy of vascular endothelial growth factor(VEGF)that may cause cardiovascular toxicity,such as hypertension via vascular dysfunction and attenuation of eNOS/NO signaling in the baroreflex afferent pathway.The aim of the current study was to evaluate the potential roles of VEGF/VEGF receptors(VEGFRs)expressed in the baroreflex afferent pathway in autonomic control of blood pressure(BP)regulation.Methods:The distribution and expression of VEGF/VEGFRs were detected in the nodose ganglia(NG)and nucleus of tractus solitary(NTS)using immunostaining and molecular approaches.The direct role of VEGF was tested by NG microinjection under physiological and hypertensive conditions.Results:Immunostaining data showed that either VEGF or VEGFR2/VEGFR3 was clearly detected in the NG and NTS of adult male rats.Microinjection of VEGF directly into the NG reduced the mean blood pressure(MBP)dose-dependently,which was less dramatic in renovascular hypertension(RVH)rats,suggesting the VEGF-mediated depressor response by direct activation of the 1st-order baroreceptor neurons in the NG under both normal and disease conditions.Notably,this reduced depressor response in RVH rats was directly caused by the downregulation of VEGFR2,which compensated the up regulation of VEGF/VEGFR3 in the NG during the development of hypertension.Conclusion:It demonstrated for the first time that the BP-lowering property of VEGF/VEGFRs signaling via the activation of baroreflex afferent function may be a common target/pathway leading to BP dysregulation in anti-angiogenic therapy.展开更多
Multiple humoral and nervous mechanisms,each influencing the cardiovascular system(CVS)with its specific dynamics and power,had been evolutionarily saved both in animals and in human organisms.Most of such mechanisms ...Multiple humoral and nervous mechanisms,each influencing the cardiovascular system(CVS)with its specific dynamics and power,had been evolutionarily saved both in animals and in human organisms.Most of such mechanisms are considered to be controllers of CVS’s function,but there is no concept clearly explaining the interaction of global and local controllers in intact human organisms under physiological or pathological conditions.Methodological and ethical constraints create practically insuperable obstacles while experiments on animals mainly concern artificial situations with certain switched-of mechanisms.Currently,mathematical modeling and computer simulations provide the most promising way for expanding and deepening our understanding of regulators’interactions.As most of CVS’s models describe only partial control mechanisms,a special model(SM)capable of simulating every combination of control mechanisms is encouraged.This paper has three goals:i)to argue the uncial modeling concept and its physiological basis,ii)to describe SM,and iii)to give basic information about SM’s test research.SM describes human hemodynamics,which is under influence of arterial baroreceptor reflexes,peripheral chemoreceptor reflexes,central(cRAS)and local(lRAS)renin-angiotensin systems,local ischemia,and autoregulation of total brain flow.SM,performed in form of special software(SS),is tested under specific endogenous and/or exogenous alterations.The physiologist using SS can easily construct the desirable configuration of regulator mechanisms,their actual state,and scenarios of computer experiments.Tests illustrated the adequateness of SM,are the first step of SM’s research.Nuances of the interaction of modeled regulator mechanisms have to be illustrated in special publications.展开更多
文摘BACKGROUND Myocardial infarction is a high-risk condition prevalent among the elderly population,often leading to adverse clinical manifestations such as reduced cardiopulmonary function,anxiety,and depression post-surgery.Consequently,cardiac rehabilitation holds immense importance in mitigating these complications.AIM To evaluate the effect of individualized cardiac rehabilitation on blood pressure variability(BPV)and baroreflex sensitivity(BRS)in elderly patients with myocardial infarction.METHODS A cohort of 74 elderly patients diagnosed with myocardial infarction and admitted to our hospital between January 2021 and January 2022 were subjected to random selection.Subsequently,all patients were divided into two groups,namely the research group(n=37)and the control group(n=37),utilizing the number table method.The control group received conventional drug treatment and nursing guidance intervention,while the study group underwent individualized cardiac rehabilitation in addition to the interventions received by the control group.All patients were continuously intervened for 12 wk,and the BPV of these two groups in the 1st wk(T0),the 4th wk(T1)and the 12th wk(T2)were compared,BRS,changes in cardiopulmonary function measures,and adverse cardiovascular events.RESULTS Of 24 h diastolic BPV,24 h systolic BPV,carbon dioxide ventilation equivalent slope of the research group were lower than those of the control group at T1 and T2,BRS,peak heart rate and systolic blood pressure product,1 min heart rate recovery were higher than those of the control group,and the incidence of adverse events in the research group was lower than that of the control group,the difference was statistically significant(P<0.05).CONCLUSION In this study,we found that after individualized cardiac rehabilitation in elderly patients with myocardial infarction,BPV and BRS can be effectively improved,cardiac function is significantly enhanced,and a better prognosis is obtained.
文摘Human cardiovascular system(CVS)and hemodynamics are critically sensitive to essential alterations of mechanical inertial forces in directions of head-legs(+Gz)or legs-head(-Gz).Typically,such alterations appear during pilotage maneuvers of modern high maneuverable airspace vehicles(HMAV).The vulnerability of pilots or passengers of HMAV to these altering forces depends on their three main characteristics:amplitude,dynamics,and duration.Special protections,proposed to minimize this vulnerability,should be improved in parallel with the increasing of these hazardous characteristics of HMAVs.Empiric testing of novel protection methods and tools is both expensive and hazardous.Therefore computer simulations are encouraged.Autonomic software(AS)for simulating and theoretical investigating of the main dynamic responses of human CVS to altering Gz is developed.AS is based on a system of quantitative mathematical models(QMM)consisting of about 1300 differential and algebraic equations.QMM describes the dynamics of both CVS(the cardiac pump function,baroreceptor control of parameters of cardiovascular net presented by means of lumped parameter vascular compartments)and non-biological variables(inertial forces,and used protections).The main function of AS is to provide physiologist-researcher by visualizations of calculated additional data concerning characteristics of both external and internal environments under high sustained accelerations and short-time microgravity.Additionally,AS can be useful as an educational tool able to show both researchers and young pilots the main hemodynamic effects caused by accelerations and acute weightlessness with and without use of different protection tools and technics.In this case,AS does help users to optimize training process aimed to ensure optimal-like human tolerance to the altered physical environment.Main physiological events appearing under different scenarios of accelerations and microgravity have been tested.
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 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supported by the American Heart Association(0730108N)the National Institute of Health’s National Heart,Lung,and Blood Institute(R01HL-098503 and R01HL-137832),USA
文摘Clinical trials and animal experimental studies have demonstrated an association of arterial baroreflex impairment with the prognosis and mortality of cardiovascular diseases and diabetes. As a primary part of the arterial baroreflex arc, the pressure sensitivity of arterial baroreceptors is blunted and involved in arterial baroreflex dysfunction in cardiovascular diseases and diabetes.Changes in the arterial vascular walls, mechanosensitive ion channels, and voltage-gated ion channels contribute to the attenuation of arterial baroreceptor sensitivity. Some endogenous substances(such as angiotensin II and superoxide anion) can modulate these morphological and functional alterations through intracellular signaling pathways in impaired arterial baroreceptors. Arterial baroreceptors can be considered as a potential therapeutic target to improve the prognosis of patients with cardiovascular diseases and diabetes.
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.
基金the Innovation Studio from School of Biomedical Engineering,Shanghai Jiao Tong University,and the Medical-Engineering Cross Project of Shanghai Jiao Tong University(No.YG2017MS53)。
文摘Baroreflex plays a significant role in modulating blood pressure for the human body.It is known that activation of the vagal nerve related to baroreflex can lead to reductions of blood pressure.However,how the vagal activities quantitatively relate with blood pressure can hardly be achieved.Here fine carbon nanotube yarn(CNTy)electrodes were adopted for recording intrafascicular vagal activities,synchronized with measurement of arterial blood pressure in a rat.Together with a novel algorithm,the results preliminarily quantified that there were six clusters of neural spikes within recorded vagal activities,and the number of individual vagal spikes correspondingly varied with blood pressure.Especially for Cluster 2,the neural activations decreased with arterial blood pressure increasing.This study can shed lights on the quantified neural mechanism underlying the control of vagal activities on blood pressure,and guide the vagal-nerve neuromodulation for treating hypertension.
基金The primary support for this study was through the Joint Capability Technology Demonstration Program within the Office of the Under Secretary of Defense(Acquisition,Technology,and Logistics)via a contract with the U.S. Special Operations Commandsupported by a research grant from The Susanne Marcus Collins Foundation+1 种基金supported by NIBIB K25 EB012236-01A1support from the Office of the Assistant Secretar y of Defense for Health Affairs through the Psychological Health/Traumatic Brain Injury Research Program,Award No.W81XWH-17-2-0057
文摘Background:Military-related post-traumatic stress(PTS)is associated with numerous symptom clusters and diminished autonomic cardiovascular regulation.Highresolution,relational,resonance-based,electroencephalic mirroringis a noninvasive,closed-loop,allostatic,acoustic stimulation neurotechnology that produces realtime translation of dominant brain frequencies into audible tones of variable pitch and timing to support the autocalibration of neural oscillations.We report clinical,autonomic,and functional effects after the use offor symptoms of military-related PTS.Methods:Eighteen service members or recent veterans(15 active-duty,3 veterans,most from special operations,1 female),with a mean age of 40.9(SD=6.9)years and symptoms of PTS lasting from 1 to 25 years,undertook19.5(SD=1.1)sessions over 12 days.Inventories for symptoms of PTS(Posttraumatic Stress Disorder Checklist–Military version,PCL-M),insomnia(Insomnia Severity Index,ISI),depression(Center for Epidemiologic Studies Depression Scale,CES-D),and anxiety(Generalized Anxiety Disorder 7-item scale,GAD-7)were collected before(Visit1,V1),immediately after(Visit2,V2),and at 1 month(Visit3,V3),3(Visit4,V4),and 6(Visit5,V5)months after intervention completion.Other measures only taken at V1 and V2 included blood pressure and heart rate recordings to analyze heart rate variability(HRV)and baroreflex sensitivity(BRS),functional performance(reaction and grip strength)testing,blood and saliva for biomarkers of stress and inflammation,and blood for epigenetic testing.Paired t-tests,Wilcoxon signed-rank tests,and a repeated-measures ANOVA were performed.Results:Clinically relevant,significant reductions in all symptom scores were observed at V2,with durability through V5.There were significant improvements in multiple measures of HRV and BRS[Standard deviation of the normal beat to normal beat interval(SDNN),root mean square of the successive differences(rMSSD),high frequency(HF),low frequency(LF),and total power,HF alpha,sequence all,and systolic,diastolic and mean arterial pressure]as well as reaction testing.Trends were seen for improved grip strength and a reduction in C-Reactive Protein(CRP),Angiotensin II to Angiotensin 1–7 ratio and Interleukin-10,with no change in DNA n-methylation.There were no dropouts or adverse events reported. Conclusion:Service members or veterans showed reductions in symptomatology of PTS,insomnia,depressive mood,and anxiety that were durable through 6 months after the use of a closed-loop allostatic neurotechnology for the autocalibration of neural oscillations.This study is the first to report increased HRV or BRS after the use of an intervention for service members or veterans with PTS.Ongoing investigations are strongly warranted.Trial registration:NCT03230890,retrospectively registered July 25,2017.
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.
文摘Despite repeated attempts to develop a unifying hypothesis that explains the clinical syndrome of heart failure(HF),no single conceptual paradigm for HF has withstood the test of time. The last model that has been developed,the neurohormonal model,has the great virtue of highlighting the role of the heart as an endocrine organ,as well as to shed some light on the key role on HF progression of neurohormones and peripheral organs and tissues beyond the heart itself. However,while survival in clinical trials based on neurohormonal antagonist drugs has improved,HF currently remains a lethal condition. At the borders of the neurohormonal model of HF,a partially unexplored path trough the maze of HF pathophysiology is represented by the feedback systems. There are several evidences,from both animal studies and humans reports,that the deregulation of baro-,ergo- and chemo-reflexes in HF patients elicits autonomic imbalance associated with parasympathetic withdrawal and increased adrenergic drive to the heart,thus fundamentally contributing to the evolution of the disease. Hence,on top of guidelinerecommended medical therapy,mainly based on neurohormonal antagonisms,all visceral feedbacks have been recently considered in HF patients as additional potential therapeutic targets.
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The brainstem is a major site in the central nervous system involved in the processing of the cardiovascular reflexes such as the baroreflex and the peripheral chemoreflex. The nucleus tractus solitarius and the rostral ventrolateral medulla are 2 important brainstem nuclei, and they play pivotal roles in autonomic cardiovascular regulation. Angiotensin II is one of the neurotransmitters involved in the processing of the known that one of the mechanisms by which angiotensin II exerts cardiovascular reflexes within the brainstem. It is well- its effect is via the activation of pathways that generate reactive oxygen species （ROS）. In the central nervous system, ROS are reported to be involved in several pathological dis- eases such as hypertension, heart failure and sleep apnea. However, little is known about the role of ROS in the processing of the cardiovascular reflexes within the brainstem. The present review mainly discussed some recent findings documenting a role for ROS in the processing of the baroreflex and the peripheral chemoreflex in the brainstem.
文摘Objective: To introduce a method to calculate cardiovascular age, a new, accurate and much simpler index for assessing cardiovascular autonomic regulatory function, based on statistical analysis of heart rate and blood pressure variability (HRV and BPV) and baroreflex sensitivity (BRS) data. Methods: Firstly, HRV and BPV of 89 healthy aviation personnel were analyzed by the conventional autoregressive (AR) spectral analysis and their spontaneous BRS was obtained by the sequence method. Secondly, principal component analysis was conducted over original and derived indices of HRV, BPV and BRS data and the relevant principal components, PCi orig and PCi deri (i=1, 2, 3,...) were obtained. Finally, the equation for calculating cardiovascular age was obtained by multiple regression with the chronological age being assigned as the dependent variable and the principal components significantly related to age as the regressors. Results: The first four principal components of original indices accounted for over 90% of total variance of the indices, so did the first three principal components of derived indices. So, these seven principal components could reflect the information of cardiovascular autonomic regulation which was embodied in the 17 indices of HRV, BPV and BRS exactly with a minimal loss of information. Of the seven principal components, PC2 orig , PC4 orig and PC2 deri were negatively correlated with the chronological age ( P <0 05), whereas the PC3 orig was positively correlated with the chronological age ( P <0 01). The cardiovascular age thus calculated from the regression equation was significantly correlated with the chronological age among the 89 aviation personnel ( r =0.73, P <0 01). Conclusion: The cardiovascular age calculated based on a multi variate analysis of HRV, BPV and BRS could be regarded as a comprehensive indicator reflecting the age dependency of autonomic regulation of cardiovascular system in healthy aviation personnel.
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.
基金supported by the National Natural Science Foundation of China(31171122,81573431,81971326 for B.-y.,Li).
文摘Objective:Oncocardiology is increasingly hot research field/topic in the clinical management of cancer with anti-angiogenic therapy of vascular endothelial growth factor(VEGF)that may cause cardiovascular toxicity,such as hypertension via vascular dysfunction and attenuation of eNOS/NO signaling in the baroreflex afferent pathway.The aim of the current study was to evaluate the potential roles of VEGF/VEGF receptors(VEGFRs)expressed in the baroreflex afferent pathway in autonomic control of blood pressure(BP)regulation.Methods:The distribution and expression of VEGF/VEGFRs were detected in the nodose ganglia(NG)and nucleus of tractus solitary(NTS)using immunostaining and molecular approaches.The direct role of VEGF was tested by NG microinjection under physiological and hypertensive conditions.Results:Immunostaining data showed that either VEGF or VEGFR2/VEGFR3 was clearly detected in the NG and NTS of adult male rats.Microinjection of VEGF directly into the NG reduced the mean blood pressure(MBP)dose-dependently,which was less dramatic in renovascular hypertension(RVH)rats,suggesting the VEGF-mediated depressor response by direct activation of the 1st-order baroreceptor neurons in the NG under both normal and disease conditions.Notably,this reduced depressor response in RVH rats was directly caused by the downregulation of VEGFR2,which compensated the up regulation of VEGF/VEGFR3 in the NG during the development of hypertension.Conclusion:It demonstrated for the first time that the BP-lowering property of VEGF/VEGFRs signaling via the activation of baroreflex afferent function may be a common target/pathway leading to BP dysregulation in anti-angiogenic therapy.
文摘Multiple humoral and nervous mechanisms,each influencing the cardiovascular system(CVS)with its specific dynamics and power,had been evolutionarily saved both in animals and in human organisms.Most of such mechanisms are considered to be controllers of CVS’s function,but there is no concept clearly explaining the interaction of global and local controllers in intact human organisms under physiological or pathological conditions.Methodological and ethical constraints create practically insuperable obstacles while experiments on animals mainly concern artificial situations with certain switched-of mechanisms.Currently,mathematical modeling and computer simulations provide the most promising way for expanding and deepening our understanding of regulators’interactions.As most of CVS’s models describe only partial control mechanisms,a special model(SM)capable of simulating every combination of control mechanisms is encouraged.This paper has three goals:i)to argue the uncial modeling concept and its physiological basis,ii)to describe SM,and iii)to give basic information about SM’s test research.SM describes human hemodynamics,which is under influence of arterial baroreceptor reflexes,peripheral chemoreceptor reflexes,central(cRAS)and local(lRAS)renin-angiotensin systems,local ischemia,and autoregulation of total brain flow.SM,performed in form of special software(SS),is tested under specific endogenous and/or exogenous alterations.The physiologist using SS can easily construct the desirable configuration of regulator mechanisms,their actual state,and scenarios of computer experiments.Tests illustrated the adequateness of SM,are the first step of SM’s research.Nuances of the interaction of modeled regulator mechanisms have to be illustrated in special publications.
