Comparative effects of central administration of naloxone and clonidine on the blood pressure and heart rate response to anterior and posterior hypothalamic stimulation

Life Sciences ◽  
1994 ◽  
Vol 54 (22) ◽  
pp. 1649-1657 ◽  
Author(s):  
Simon W. Rabkin
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Response ◽  
Hypothalamic Stimulation ◽  
Central Administration ◽  
Posterior Hypothalamic Stimulation

Temporal relationships of barosensory attenuation in conscious rabbits

1976 ◽  
Vol 230 (6) ◽  
pp. 1480-1486 ◽  
Author(s):  
MP Gimpl ◽  
AL Brickman ◽  
MP Kaufman ◽  
N Schneiderman
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiovascular Responses ◽  
Hypothalamic Stimulation ◽  
Aortic Nerve ◽  
Temporal Relationships ◽  
Train Stimulation ◽  
Posterior Hypothalamic Stimulation ◽  
Simple Summation ◽  
Stimulation Of

Electrical stimulation of anterior or posterior hypothalamus with 10-s trains elicited heart rate and blood pressure decreases. Presentation of anterior hypothalamic stimulation coincident with or 5, 10, or 15 s prior to 5-s train stimulation of aortic nerve (AN) summated with depressor-decelerator responses to AN stimulation. The summating effect was more pronounced for heart rate than for blood pressure. Simultaneous onset of AN and posterior hypothalamic stimulation did not influence AN responses. In contrast, when AN stimulation was delayed until 5, 10, or 15 s after onset of posterior hypothalamic stimulation, small, moderate, and full attenuation of AN responses occurred, respectively. Since AN and posterior hypothalamic stimulation each led to depressor-decelerator responses, attenuation of AN responses cannot be attributed to simple summation of cardiovascular responses elicited by intracranial and aortic nerve stimulation.

Cardiac autonomic dysfunction in obese subjects

1989 ◽  
Vol 76 (6) ◽  
pp. 567-572 ◽  
Author(s):  
Marco ROSSI ◽  
Giuliano Marti ◽  
Luigi Ricordi ◽  
Gabriele Fornasari ◽  
Giorgio Finardi ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Body Mass Index ◽  
Heart Rate ◽  
Autonomic Dysfunction ◽  
Cross Correlation ◽  
Heart Rate Response ◽  
Valsalva Manoeuvre ◽  
Deep Breathing ◽  
Cardiac Autonomic Dysfunction ◽  
Obese Subjects

1. The prevalence of cardiac autonomic alterations was evaluated in 23 obese subjects with body mass index 37.2 ± 3.03 kg/m2 (mean ± sd), compared with 78 controls with body mass index 22.5 ± 2.6 kg/m2 (P < 0.001). 2. Cardiac autonomic function was assessed by four standard tests (heart rate response to deep breathing and to the Valsalva manoeuvre, systolic blood pressure fall after standing and diastolic pressure rise during handgrip) and by the cross-correlation test, a new method of computerized analysis of respiratory sinus arrhythmia based on spectral analysis of electrocardiographic and respiratory signals. 3. Considering tests indicative of parasympathetic function, only the heart rate response to the deep breathing and the cross-correlation test were significantly lower in the obese than in the control group [deep breathing = 13.95 ± 8.65 beats/min (mean ± sd) vs 24.5 ± 7.65, P < 0.001; cross-correlation 4.28 ± 0.74 units vs 5.14 ± 0.63, P < 0.001]. Deep breathing and/or cross-correlation were abnormal in 10 (43.5%) obese subjects (deep breathing: seven subjects, cross-correlation: eight subjects). No significant difference between groups was found for the response to the Valsalva manoeuvre: the Valsalva ratio was 1.69 ± 0.45 in obese subjects and 1.88 ± 0.33 in controls (P = NS). The Valsalva ratio was abnormal in three obese subjects. 4. No significant differences were found between groups for tests indicative of sympathetic function. The rise in diastolic blood pressure after handgrip was 12.6 ± 6.2 mmHg (1.67 ± 0.82 kPa) in obese subjects and 18.2 ± 4.9 mmHg (2.42 ± 0.65 kPa) in controls (P = NS), and the fall in systolic blood pressure after standing was −6.8 ± 8.6 mmHg (−0.90 ± 1.14 kPa) in obese subjects and −6.9 ± 10.4 mmHg (−0.91 ± 1.38 kPa) in controls (P = NS). The handgrip test was abnormal in four obese subjects, while no obese subject had an abnormal blood pressure response to standing. 5. Our findings suggest a high incidence of cardiac autonomic dysfunction in obese subjects. Since cardiac autonomic alterations have been shown to be involved in the mechanisms of cardiac sudden death, our data suggest a possible role of autonomic dysfunction in the increased risk for sudden death in obesity.

scholarly journals Vascular resistance arm of the baroreflex: methodology and comparison with the cardiac chronotropic arm

2020 ◽  
Vol 128 (5) ◽  
pp. 1310-1320
Author(s):  
J. Krohova ◽  
L. Faes ◽  
B. Czippelova ◽  
R. Pernice ◽  
Z. Turianikova ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Vascular Resistance ◽  
Vascular Tone ◽  
Heart Rate Response ◽  
Peripheral Vascular Resistance ◽  
Noninvasive Measurement ◽  
Peripheral Vascular ◽  
Pressure Changes

Baroreflex response consists of several arms, but the cardiac chronotropic arm (blood pressure changes evoking heart rate response) is usually analyzed. This study introduces a method to assess the vascular baroreflex arm with the continuous noninvasive measurement of peripheral vascular resistance as an output considering causality in the interaction between oscillations and slower dynamics of vascular tone changes. We conclude that although vascular baroreflex arm involvement becomes dominant during orthostasis, gain of this interaction is relatively stable.

Central angiotensin II-induced pressor responses and neural activity in utero and hypothalamic angiotensin receptors in preterm ovine fetus

2004 ◽  
Vol 286 (4) ◽  
pp. H1507-H1514 ◽  
Author(s):  
Zhice Xu ◽  
Lijun Shi ◽  
Jiaming Yao
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
In Utero ◽  
Angiotensin Receptors ◽  
Ang Ii ◽  
Central Administration ◽  
Pressor Responses ◽  
Ovine Fetus ◽  
Fos Expression ◽  
Sympathetic Pathway

The central renin-angiotensin system is important in the control of blood pressure in the adult. However, few data exist about the in utero development of central angiotensin-mediated pressor responses. Our recent studies have shown that the application of ANG II into the fetal brain can increase blood pressure at near term. The present study determined fetal blood pressure and heart rate in response to a central application of ANG II in the chronically prepared preterm ovine fetus, determined the action sites marked by c-Fos expression in the fetal central pathways after intracerebroventricular injection of ANG II in utero, and determined angiotensin subtype 1 receptors in the fetal hypothalamus. Central injection of ANG II significantly increased fetal mean arterial pressure (MAP). Adjusted fetal MAP against amniotic pressure was also increased by ANG II. Fetal heart rate was subsequently decreased after the central administration of ANG II and/or the increase of blood pressure. ANG II induced c-Fos expression in the central putative cardiovascular area, the paraventricular nuclei in the brain sympathetic pathway. Application of ANG II also caused intense Fos immunoreactivity in the tractus solitarius nuclei in the hindbrain. In addition, intense angiotensin subtype 1 receptors were expressed in the hypothalamus at preterm. These data demonstrate that central ANG II-related pressor centers start to function as early as at preterm and suggest that the central angiotensin-related sympathetic pathway is likely intact in the control of blood pressure in utero.

Heart rate during exercise with leg vascular occlusion in spinal cord-injured humans

1999 ◽  
Vol 86 (3) ◽  
pp. 806-811 ◽  
Author(s):  
M. Kjær ◽  
F. Pott ◽  
T. Mohr ◽  
P. Linkis ◽  
P. Tornøe ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Heart Rate ◽  
Oxygen Uptake ◽  
Heart Rate Response ◽  
Vascular Occlusion ◽  
Voluntary Exercise ◽  
Feedback Mechanisms ◽  
Cord Injury ◽  
Neural Feedback

Feed-forward and feedback mechanisms are both important for control of the heart rate response to muscular exercise, but their origin and relative importance remain inadequately understood. To evaluate whether humoral mechanisms are of importance, the heart rate response to electrically induced cycling was studied in participants with spinal cord injury (SCI) and compared with that elicited during volitional cycling in able-bodied persons (C). During voluntary exercise at an oxygen uptake of ∼1 l/min, heart rate increased from 66 ± 4 to 86 ± 4 (SE) beats/min in seven C, and during electrically induced exercise at a similar oxygen uptake in SCI it increased from 73 ± 3 to 110 ± 8 beats/min. In contrast, blood pressure increased only in C (from 88 ± 3 to 99 ± 4 mmHg), confirming that, during exercise, blood pressure control is dominated by peripheral neural feedback mechanisms. With vascular occlusion of the legs, the exercise-induced increase in heart rate was reduced or even eliminated in the electrically stimulated SCI. For C, heart rate tended to be lower than during exercise with free circulation to the legs. Release of the cuff elevated heart rate only in SCI. These data suggest that humoral feedback is of importance for the heart rate response to exercise and especially so when influence from the central nervous system and peripheral neural feedback from the working muscles are impaired or eliminated during electrically induced exercise in individuals with SCI.

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