Cardiovascular changes induced by central hypertonic saline are accompanied by glutamate release in awake rats

2001 ◽  
Vol 281 (4) ◽  
pp. R1224-R1231 ◽  
Author(s):  
Qing-Hua Jin ◽  
Yuto Ueda ◽  
Yuta Ishizuka ◽  
Takato Kunitake ◽  
Hiroshi Kannan
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nmda Receptor ◽  
Hypertonic Saline ◽  
Glutamate Release ◽  
Cardiovascular Responses ◽  
Brain Microdialysis ◽  
Salt Loading ◽  
Local Release

To elucidate neurochemical mechanisms responsible for cardiovascular responses induced by central salt loading, we directly perfused the paraventricular nucleus (PVN) of the hypothalamus region with hypertonic saline (0.3 or 0.45 M) by using an in vivo brain microdialysis technique. We then measured the extracellular concentrations of glutamate in the PVN region in conscious rats along with the blood pressure and heart rate. Blood pressure, heart rate, and glutamate levels were increased by perfusion of 0.45 M saline; however, they did not change by perfusion of 0.3 M saline. Next, we examined the possible involvement of glutamate in the cardiovascular responses induced by hypertonic saline. Dizocilpine, a noncompetitive antagonist of the N-methyl-d-aspartate (NMDA) receptor, attenuated the increases of blood pressure and heart rate, although 6-cyano-7-nitroquinoxaline-2,3-dione, an antagonist of the non-NMDA receptor, did not affect the blood pressure and heart rate. Our results show that local perfusion of the hypothalamic PVN region with hypertonic saline elicits a local release of glutamate, which may act via NMDA-type glutamate receptors to produce cardiovascular responses.

Cardiovascular responses in vivo to angiotensin II and the peptide antagonist saralasin in rainbow trout Oncorhynchus mykiss.

1998 ◽  
Vol 201 (2) ◽  
pp. 267-272 ◽  
Author(s):  
J Fuentes ◽  
F B Eddy
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Rainbow Trout ◽  
Angiotensin Ii ◽  
Renin Angiotensin System ◽  
Cardiovascular Responses ◽  
Hypotensive Effect ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Aortic Blood Pressure

The effects of [Asn1,Val5]-angiotensin II (AngII) and [Sar1,Val5, Ala8]-angiotensin II (saralasin) on dorsal aortic blood pressure, pulse pressure and heart rate were examined in rainbow trout in vivo. AngII when administered as a single dose of 25 microg kg-1 induced a biphasic response in blood pressure, with a significant hypertensive response during the initial 10 min, followed by a significant hypotension of 70-75 % compared with the initial blood pressure after 50 min and continuing until approximately 80 min post-injection. The co-administration of AngII (25 microg kg-1) and saralasin (50 microg kg-1) resulted in the same hypertensive response during the initial phase, but abolished the hypotensive effect of AngII. Heart rate was significantly increased in response to AngII, but the administration of AngII and saralasin together attenuated the increase by approximately 44 %. Stimulation of the endogenous renin-angiotensin system using a vasodilator, sodium nitroprusside, significantly increased drinking rate in rainbow trout fry, a response inhibited by saralasin, indicating a role for AngII-induced hypotension in drinking. For the first time, a decrease in blood pressure in response to AngII in vivo has been demonstrated in fish, and this is discussed in relation to homeostasis of blood pressure and a possible role in the control of drinking.

Cardiovascular Responses to Muscle Stretching: A Systematic Review and Meta-analysis

2021 ◽  
Author(s):  
Ewan Thomas ◽  
Marianna Bellafiore ◽  
Ambra Gentile ◽  
Antonio Paoli ◽  
Antonio Palma ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiovascular System ◽  
Vascular Function ◽  
Meta Analysis ◽  
Random Effect ◽  
Cardiovascular Responses ◽  
Qualitative Description ◽  
Cross Sectional ◽  
Quantitative Synthesis

AbstractThe aim of this study will be to review the current body of literature to understand the effects of stretching on the responses of the cardiovascular system. A literature search was performed using the following databases: Scopus, NLM Pubmed and ScienceDirect. Studies regarding the effects of stretching on responses of the cardiovascular system were investigated. Outcomes regarded heart rate(HR), blood pressure, pulse wave velocity (PWV of which baPWV for brachial-ankle and cfPWV for carotid-femoral waveforms), heart rate variability and endothelial vascular function. Subsequently, the effects of each outcome were quantitatively synthetized using meta-analytic synthesis with random-effect models. A total of 16 studies were considered eligible and included in the quantitative synthesis. Groups were also stratified according to cross-sectional or longitudinal stretching interventions. Quality assessment through the NHLBI tools observed a “fair-to-good” quality of the studies. The meta-analytic synthesis showed a significant effect of d=0.38 concerning HR, d=2.04 regarding baPWV and d=0.46 for cfPWV. Stretching significantly reduces arterial stiffness and HR. The qualitative description of the studies was also supported by the meta-analytic synthesis. No adverse effects were reported, after stretching, in patients affected by cardiovascular disease on blood pressure. There is a lack of studies regarding vascular adaptations to stretching.

Cardiovascular Responding during Anger and Fear Imagery

1982 ◽  
Vol 50 (1) ◽  
pp. 219-230 ◽  
Author(s):  
Richard J. Roberts ◽  
Theodore C. Weerts
Keyword(s):  
College Students ◽  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Scene Change ◽  
Emotional Responding ◽  
Analysis Of Change ◽  
Screening Interview

This study was designed to determine if visualization of anger- and fear-provoking scenes produced differential physiological patterns similar to those produced by in vivo manipulations. Normotensive college students were selected on the basis of their responses to newly developed Anger and Fear/Anxiety questionnaires and for their ability to construct arousing scenes during a screening interview. In a 2 × 2 design (intensity × emotion), four scenes (high and low anger, high and low fear) were constructed individually for each of 16 subjects to imagine. Diastolic blood pressure, systolic blood pressure, and heart rate were monitored during visualization of each scene. Change in diastolic blood pressure was significantly greater for high anger than for high fear as predicted. Analysis of change in heart rate and systolic blood pressure showed significant effects for intensity only. These results provide further support for the concept of physiological differentiation in human emotion and suggest the utility of imagery for systematic study of human emotional responding.

Cardiovascular responses to head-stand posture

1963 ◽  
Vol 18 (5) ◽  
pp. 987-990 ◽  
Author(s):  
Shanker Rao
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
High Pressure ◽  
Blood Flow ◽  
Arterial Pressure ◽  
Skin Temperature ◽  
Cardiovascular Responses ◽  
Posterior Tibial Artery ◽  
Nervous Control ◽  
Posterior Tibial

Reports of cardiovascular responses to head-stand posture are lacking in literature. The results of the various responses, respectively, to the supine, erect, and head-stand posture, are as follows: heart rate/min 67, 84, and 69; brachial arterial pressure mm Hg 92, 90, and 108; posterior tibial arterial pressure mm Hg 98, 196, and 10; finger blood flow ml/100 ml min 4.5, 4.4, and 5.2; toe blood flow ml/100 ml min 7.1, 8.1, and 3.4; forehead skin temperature C 34.4, 34.0 and 34.3; dorsum foot skin temperature C 28.6, 28.2, and 28.2. It is inferred that the high-pressure-capacity vessels between the heart level and posterior tibial artery have little nervous control. The high-pressure baroreceptors take active part in postural adjustments of circulation. The blood pressure equating mechanism is not as efficient when vital tissues are pooled with blood as when blood supply to them is reduced. man; heart rate; blood flow; skin temperature Submitted on January 3, 1963

scholarly journals Tai-chi-chuan and yoga onpostexercise hypotension: comparison to aerobic and resistance exercise

2016 ◽  
Vol 29 (3) ◽  
pp. 543-552
Author(s):  
João Douglas Alves ◽  
Jorge Luiz de Brito Gomes ◽  
Caio Victor Coutinho de Oliveira ◽  
José Victor de Miranda Henriques Alves ◽  
Fabiana Ranielle de Siqueira Nogueira ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Young Women ◽  
Tai Chi ◽  
Cardiovascular Effects ◽  
Cardiovascular Responses ◽  
Tai Chi Chuan ◽  
Post Exercise ◽  
Significant Difference ◽  
Apparently Healthy

Abstract Introduction: Tai-Chi-Chuan and Yoga have becoming popular practices. However is unclear the cardiovascular effects, and if they present similar behavior to aerobic and resistance sessions. Objective: To evaluate the cardiovascular responses during the session and post-exercise hypotension (PEH) of Tai Chi Chuan (TS) and Yoga (YS) in comparison to aerobic (AS) and resistance (SR) exercises. Methods: Fourteen young women (22.3 ± 2 years) apparently healthy performed four sessions (AS, RS, TS and YS). The heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP) were recorded at resting, during (every 10 minutes) and until 50 minutes of recovery. Results: AS, RS, TS e YS showed significant increase in HR compared to resting.AS at 10, 30 e 50 minutes in relation to RS, TS e YS. The RS in relation to TS and YS at 10, 30 and 50 minutes. No significant difference between TS and YS. SBP was significantly increased in AS, RS, TS e YS at 10, 30 e 50 minutes during the session, in relation to rest. AS was significantly higher at 30 e 50 minutes than RS and higher than TS and YS at 10, 30 e 50 minutes. No significant difference in DBP. For PEH, AS, RS and TS significantly reduced at 10, 30 and 50 minutes. YS reduced at 50 minutes. No significant diastolic PEH. Conclusion: TS and YS showed as safe alternatives of exercising in the normotensive young adult woman, despite having lower values, they promote similar hemodynamic behavior to AS and RS.

Ascending pathways mediating somatoautonomic reflexes in exercising dogs

1987 ◽  
Vol 62 (3) ◽  
pp. 1186-1191 ◽  
Author(s):  
J. W. Kozelka ◽  
G. W. Christy ◽  
R. D. Wurster
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Surgical Techniques ◽  
Arterial Occlusion ◽  
Cardiovascular Responses ◽  
Spinal Pathways ◽  
Arterial Blood ◽  
Bilateral Carotid ◽  
Dorsolateral Funiculus ◽  
Carotid Arterial

The ascending spinal pathways mediating somatocardiovascular reflexes during exercise were studied in unanesthetized dogs by placing lesions in the lumbar spinal cord. After training to run on a treadmill with hindlimbs only, 20 dogs were anesthetized and instrumented using sterile surgical techniques. To chronically record heart rate and arterial blood pressure, the aorta was cannulated via the omocervical artery. To test the intactness of descending spinal sympathetic pathways, reflex pressor responses to baroreceptor hypotension were produced by bilateral carotid arterial occlusion using pneumatic vessel occluders placed around the common carotid arteries. To generate transient ischemic exercise (120 s), a pneumatic occluder was placed around the left iliac artery. Eight to 10 days after instrumentation, blood pressure and heart rate were monitored at rest and during hindlimb running with and without simultaneous iliac arterial occlusion. The modest pressor response and tachycardia elicited by hindlimb exercise were markedly augmented by simultaneous hindlimb ischemia (i.e., iliac arterial occlusion). Lesion placement in the dorsolateral sulcus area and the dorsolateral funiculus at L2 significantly reduced the blood pressure and heart rate responses to simultaneous exercise occlusion. The cardiovascular responses to nonischemic exercise and bilateral carotid arterial occlusion were not altered by such spinal sections. It is concluded that in the dog the ascending spinal pathways mediating cardiovascular responses to ischemic exercise are located in the lateral funiculus, including the dorsolateral sulcus area and dorsolateral funiculus.

Reciprocal rat chromosome 2 congenic strains reveal contrasting blood pressure and heart rate QTL

2002 ◽  
Vol 10 (3) ◽  
pp. 199-210 ◽  
Author(s):  
Adamu Alemayehu ◽  
Laura Breen ◽  
Drahomira Krenova ◽  
Morton P. Printz
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Spontaneously Hypertensive Rat ◽  
Cardiovascular Responses ◽  
Chromosome 2 ◽  
Spontaneously Hypertensive ◽  
Congenic Strains ◽  
Multiple Blood ◽  
Wistar Kyoto ◽  
Chromosome Segments

Evidence exists implying multiple blood pressure quantitative trait loci (QTL) on rat chromosome 2. To examine this possibility, four congenic strains and nine substrains were developed with varying size chromosome segments introgressed from the spontaneously hypertensive rat (SHR/lj) and normotensive Wistar-Kyoto rat (WKY/lj) onto the reciprocal genetic background. Cardiovascular phenotyping was conducted with telemetry over extended periods during standard salt (0.7%) and high-salt (8%) diets. Our results are consistent with at least three independent pressor QTL: transfer of SHR/lj alleles to WKY/lj reveals pressor QTL within D2Rat21-D2Rat27 and D2Mgh10-D2Rat62, whereas transfer of WKY/lj D2Rat161-D2Mit8 to SHR/lj reveals a depressor locus. Our results also suggest a depressor QTL in SHR/lj located within D2Rat161-D2Mgh10. Introgressed WKY/lj segments also reveal a heart rate QTL within D2Rat40-D2Rat50 which abolished salt-induced bradycardia, dependent upon adjoining SHR/lj alleles. This study confirms the presence of multiple blood pressure QTL on chromosome 2. Taken together with our other studies, we conclude that rat chromosome 2 is rich in alleles for cardiovascular and behavioral traits and for coordinated coupling between behavior and cardiovascular responses.

Acute Cardiovascular Responses to Self-selected Intensity Exercise in Parkinson's Disease

2021 ◽  
Author(s):  
Hélcio Kanegusuku ◽  
Gabriel Grizzo Cucato ◽  
Paulo Longano ◽  
Erika Okamoto ◽  
Maria Elisa Pimentel Piemonte ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Parkinson’S Disease ◽  
Heart Rate ◽  
Parkinson's Disease ◽  
Pulse Wave ◽  
Augmentation Index ◽  
Cardiovascular Responses ◽  
Cycle Ergometer ◽  
Control Session ◽  
Wave Analysis

AbstractParkinson’s disease patients frequently present cardiovascular dysfunction. Exercise with a self-selected intensity has emerged as a new strategy for exercise prescription aiming to increase exercise adherence. Thus, the current study evaluated the acute cardiovascular responses after a session of aerobic exercise at a traditional intensity and at a self-selected intensity in Parkinson’s disease patients. Twenty patients (≥ 50 years old, Hoehn & Yahr 1–3 stages) performed 3 experimental sessions in random order: Traditional session (cycle ergometer, 25 min, 50 rpm, 60–80% maximum heart rate); Self-selected intensity: (cycle ergometer, 25 min, 50 rpm with self-selected intensity); and Control session (resting for 25 min). Before and after 30 min of intervention, brachial and central blood pressure (auscultatory method and pulse wave analysis, respectively), cardiac autonomic modulation (heart rate variability), and arterial stiffness (pulse wave analysis) were evaluated. Brachial and central systolic and diastolic blood pressure, heart rate, and the augmentation index increased after the control session, whereas no changes were observed after the exercise sessions (P<0.01). Pulse wave velocity and cardiac autonomic modulation parameters did not change after the three interventions. In conclusion, a single session of traditional intensity or self-selected intensity exercises similarly blunted the increase in brachial and central blood pressure and the augmentation index compared to a non-exercise control session in Parkinson’s disease patients.

Measurement of sympathetic nerve activity in the unanesthetized rat

1989 ◽  
Vol 67 (1) ◽  
pp. 250-255 ◽  
Author(s):  
J. P. Fluckiger ◽  
G. Gremaud ◽  
B. Waeber ◽  
A. Kulik ◽  
A. Ichino ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Pressure ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Blood Pressure Reduction ◽  
Response Curves ◽  
Nerve Activity ◽  
Dose Dependent

A new system was developed in our laboratory to continuously monitor intra-arterial pressure, heart rate, and sympathetic nerve activity in unanesthetized rats. The animals were prepared 24 h before the start of the experiments. Sympathoneural traffic was measured at the level of splanchnic nerve. The amplitude of the spikes recorded at this level was utilized to express sympathetic nerve activity. The amplitude of the residual electroneurogram signal present 30 min after the rats were killed was 32 +/- 2 mV (mean +/- SE; n = 11). For analysis, these background values were subtracted from values determined in vivo. The nerve we studied contains postganglionic fibers, since electrical activity decreased in response to ganglionic blockade with pentolinium (1.25 mg/min iv for 4 min). The amplitude of spikes fell by 43 +/- 4% (n = 4). Sympathetic nerve activity was highly reproducible at a 24-h interval (104 +/- 26 vs. 111 +/- 27 mV for the amplitude of spikes; n = 11). Dose-response curves to the alpha 1-stimulant methoxamine and to bradykinin were established in four rats. The increase in blood pressure induced by methoxamine caused a dose-dependent fall in sympathetic nerve activity, whereas the blood pressure reduction resulting from bradykinin was associated with a dose-dependent activation of sympathetic drive. These data therefore indicate that it is possible with out system to accurately measure sympathetic nerve activity in the awake rat, together with intra-arterial pressure and heart rate.

Autonomic mechanisms underlying area postrema stimulation-induced cardiovascular responses in rats

1991 ◽  
Vol 261 (1) ◽  
pp. R1-R8 ◽  
Author(s):  
A. V. Ferguson ◽  
P. Smith
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Rate Control ◽  
Area Postrema ◽  
Cardiovascular Responses ◽  
Pressure Control ◽  
Blocking Agent ◽  
Adrenergic Blockade ◽  
Neural Pathways ◽  
Heart Rate Control

Experiments were designed to examine the autonomic mechanisms underlying the decreases in blood pressure and heart rate elicited by electrical stimulation in the rat area postrema (AP). Vagotomy was found to significantly reduce the bradycardia observed in response to AP stimulation (control -123.5 +/- 23.5 beats/min; vagotomized -7 +/- 5.4 beats/min; P less than 0.001) but was without significant effect on blood pressure responses. Hexamethonium significantly reduced both heart rate (control -225.5 +/- 11.9 beats/min; hexamethonium -5.5 +/- 2.8 beats/min; P less than 0.001) and depressor (control -35.4 +/- 4.7 mmHg; hexamethonium -6.4 +/- 0.8 mmHg; P less than 0.001) responses to such stimulation, whereas combined alpha- and beta-adrenergic blockade was without effect. The muscarinic blocking agent atropine also abolished both blood pressure (control -22.0 +/- 4.3 mmHg; atropine 2.8 +/- 4.4 mmHg; P less than 0.01) and heart rate (control -187.0 +/- 41.9 beats/min; atropine 8.8 +/- 2.6 beats/min; P less than 0.01) responses to AP stimulation. These data suggest that AP stimulation influences two separate neural pathways eliciting distinct cardiovascular responses. It would appear that activation of one of these pathways results in activation of vagal efferents to the heart and thus bradycardia. A second parallel pathway influenced by AP stimulation apparently elicits depressor response through actions on cholinergic muscarinic receptors.

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