Postprandial changes in supine and erect heart rate, systemic blood pressure and plasma noradrenaline and renin activity in normal subjects

The purpose of the study was to evaluate the changes of respiratory rate, systemic blood pressure and heart rate variability parameters (HRV) during orthostasis in anaesthetized rabbits. Furthermore, these changes were influenced by affecting the renin-angiotensin-aldosterone (RAA) system and autonomic nervous system (ANS) to study the mechanisms participating in activity of spectral frequency bands of HRV in rabbits. Ten adult rabbits (Chinchilla) were anaesthetized by ketamine and flunitrazepam. The systemic blood pressure, tidal volume and respiratory rate were measured. HRV was evaluated by microcomputer system VariaPulse TF3E. The R-R intervals were derived from the electrocardiogram signal from subcutaneous needle electrodes. The evaluation of HRV in very low (VLF; 0.01-0.05 Hz), low (LF; 0.05-0.15 Hz) and high frequency bands (HF; 0.15-2.0 Hz) was made and parameters of frequency and time analysis were calculated. The measurements were made in horizontal (supine) position, in orthostasis (the angle of 60 °) and again in supine position before and after enalapril (0.5 mg/kg b.w.), metipranolol (0.2 mg/kg b.w.), and after subsequent bilateral cervical vagotomy. The orthostasis in anaesthetized rabbits is accompanied by depression of respiratory rate reversed only by vagotomy. Furthermore, decrease of systemic blood pressure, unchanged heart rate and increased characteristics of heart rate variability were found, with predominant increase of spectral power in LF and VLF bands. This elevation can be eliminated only by complete blockade of ANS. Although the participation of ANS or RAA system in modification of individual HRV frequency bands is not as specific as in humans, we confirmed the participation of RAA system in determination of the VLF band.

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Neural mechanism underlying basilar arterial constriction by intracisternal L-NNA in anesthetized dogs

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1993.265.1.h103 ◽

1993 ◽

Vol 265 (1) ◽

pp. H103-H107 ◽

Cited By ~ 7

Author(s):

N. Toda ◽

K. Ayajiki ◽

T. Okamura

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Cerebral Arteries ◽

Neural Mechanism ◽

Systemic Blood Pressure ◽

Systemic Blood ◽

Anesthetized Dogs ◽

Arterial Constriction ◽

Synthase Inhibitor

Basilar arterial diameters were angiographically measured in anesthetized dogs in which systemic blood pressure and heart rate were also monitored. Injections of NG-nitro-L-arginine (L-NNA), a NO synthase inhibitor, into the cisterna magna produced a significant, persistent decrease in arterial diameter, the effect being reversed by intracisternal injections of L-arginine. The vasoconstrictor effect of L-NNA was diminished in dogs treated with hexamethonium. On the other hand, treatment with phentolamine in a dose sufficient to lower blood pressure to a level similar to that attained with hexamethonium did not inhibit, but rather potentiated, the effect of intracisternal L-NNA. Nicotine injected into the vertebral artery significantly dilated the basilar artery. The effect was abolished by treatment with L-NNA applied intracisternally, the inhibition being reversed by the addition of L-arginine. Systemic blood pressure and heart rate were not altered by intracisternally applied L-NNA and L-arginine. These findings support the hypothesis that basilar arterial constriction caused by intracisternal L-NNA is associated with a suppression of NO synthesis in nitroxidergic nerves innervating the cerebroarterial wall rather than an elimination of basal release of NO from the endothelium. Functional importance of nitroxidergic vasodilator innervation in cerebral arteries in vivo is thus clarified.

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Baroreceptor influence on postural changes in blood pressure and carotid blood flow

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1963.205.2.360 ◽

1963 ◽

Vol 205 (2) ◽

pp. 360-364 ◽

Cited By ~ 18

Author(s):

Francis L. Abel ◽

John H. Pierce ◽

Warren G. Guntheroth

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Carotid Sinus ◽

Systemic Blood Pressure ◽

Systemic Blood ◽

Carotid Blood Flow ◽

Postural Changes ◽

Nembutal Anesthesia

The effects of 30° head-down and head-up tilting on mean systemic blood pressure, carotid blood flow, and heart rate were studied in 16 dogs under morphine and Nembutal anesthesia. The tilting procedure was further repeated after denervation of the carotid sinus and aortic arch baroreceptors and after administration of a dihydrogenated ergot alkaloid mixture (Hydergine). The results indicate that the drop in pressure in the head-down position is primarily due to baroreceptor activity and that the baroreceptors are necessary for compensatory vasoconstriction on head-up tilting. Carotid blood flow decreased in both tilted positions in the control animals; the possible relationship to cerebral blood flow is discussed.

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Renin and Aldosterone Release during Sympathetic Stimulation in Tetraplegia

Clinical Science ◽

10.1042/cs0600399 ◽

1981 ◽

Vol 60 (4) ◽

pp. 399-404 ◽

Cited By ~ 17

Author(s):

C. J. Mathias ◽

H. L. Frankel ◽

I. B. Davies ◽

V. H. T. James ◽

W. S. Peart

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Plasma Renin Activity ◽

Diastolic Blood Pressure ◽

Pressor Response ◽

Plasma Renin ◽

Normal Subjects ◽

Plasma Aldosterone ◽

Renin Activity ◽

Sympathetic Stimulation

1. The effect of endogenous sympathetic stimulation (induced by urinary bladder stimulation) and intravenous infusion of noradrenaline and isoprenaline on blood pressure, heart rate and levels of plasma renin activity and plasma aldosterone were studied in six tetraplegic patients. Data from infusion studies were compared with data from six normal subjects studied in an identical manner. 2. Bladder stimulation in the tetraplegic patients caused a marked rise in blood pressure and fall in heart rate, but no change in plasma renin activity or plasma aldosterone. 3. Noradrenaline infusion resulted in an enhanced pressor response in the tetraplegic patients when compared with the normal subjects. Heart rate fell in both groups. Plasma renin activity and plasma aldosterone did not change in either group. 4. Isoprenaline infusion caused a fall in both systolic and diastolic blood pressure in the tetraplegic patients, unlike the normal subjects in whom there was a rise in systolic and a fall in diastolic blood pressure. Heart rate and plasma renin activity rose in both groups. Plasma aldosterone did not change in either group. 5. We conclude that in tetraplegic patients neither endogenous sympathetic stimulation by bladder stimulation nor infusion of noradrenaline raises plasma renin activity. Isoprenaline increases plasma renin activity to the same extent as in normal subjects. Renin release mechanisms in tetraplegic patients therefore do not appear to be hypersensitive to catecholamines. Plasma aldosterone is not influenced by any of the stimuli.

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Monitoring of standard hemodynamic parameters: Heart rate, systemic blood pressure, atrial pressure, pulse oximetry, and end-tidal CO2

Pediatric Critical Care Medicine ◽

10.1097/pcc.0b013e318220e7ea ◽

2011 ◽

Vol 12 ◽

pp. S2-S11 ◽

Cited By ~ 32

Author(s):

V. Ben Sivarajan ◽

Desmond Bohn

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Pulse Oximetry ◽

Pressure Pulse ◽

Systemic Blood Pressure ◽

Atrial Pressure ◽

Hemodynamic Parameters ◽

Systemic Blood ◽

End Tidal ◽

End Tidal Co2

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PROGNOSTIC VALUE OF HEART RATE AND SYSTEMIC BLOOD PRESSURE IN PULMONARY ARTERIAL HYPERTENSION

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(10)61444-1 ◽

2010 ◽

Vol 55 (10) ◽

pp. A154.E1443

Author(s):

Malcolm M. Bersohn ◽

Shelley Shapiro ◽

Michelle P. Turner ◽

Glenna Traiger ◽

Adaani E. Frost

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Pulmonary Arterial Hypertension ◽

Arterial Hypertension ◽

Prognostic Value ◽

Systemic Blood Pressure ◽

Systemic Blood ◽

Pulmonary Arterial

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P504 HEMODYNAMIC RESPONSE TO NON-SELECTIVE BETA BLOCKERS DESPITE LACK OF EFFECTS ON HEART RATE AND SYSTEMIC BLOOD PRESSURE

Journal of Hepatology ◽

10.1016/s0168-8278(14)60666-8 ◽

2014 ◽

Vol 60 (1) ◽

pp. S237

Author(s):

S. Bota ◽

M. Mandorfer ◽

P. Schwabl ◽

P. Salzl ◽

A. Ferlitsch ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Beta Blockers ◽

Systemic Blood Pressure ◽

Hemodynamic Response ◽

Systemic Blood

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Influence of Sympatholytic Drugs on the Cardiovascular Response to Isometric Exercise

Clinical Science ◽

10.1042/cs0600139 ◽

1981 ◽

Vol 60 (2) ◽

pp. 139-143 ◽

Cited By ~ 7

Author(s):

S. J. Watt ◽

R. D. Thomas ◽

P. W. Belfield ◽

P. W. Goldstraw ◽

S. H. Taylor

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Healthy Subjects ◽

Cardiovascular Response ◽

Pressor Response ◽

Isometric Exercise ◽

Systemic Blood Pressure ◽

Isometric Handgrip ◽

Systemic Blood ◽

Oral Doses

1. The effects of single oral doses of various sympatholytic drugs on the heart rate and blood pressure increases during isometric handgrip contraction were studied in six healthy subjects. 2. Bethanidine reduced both the systolic and diastolic increases in pressure. Clonidine reduced the systolic but not the diastolic increase. Oxprenolol alone or in combination with phentolamine or phenyoxybenzamine failed to influence the pressor response. 3. The increase in systemic blood pressure associated with sustained contraction of voluntary muscle appears to be relatively resistant to acute sympathetic adrenoreceptor blockade in man.

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Endogenous Opioids Modulate Central Nervous System Blood Pressure Control in Man

Clinical Science ◽

10.1042/cs063331s ◽

1982 ◽

Vol 63 (s8) ◽

pp. 331s-333s ◽

Cited By ~ 9

Author(s):

P. C. Rubin ◽

Kathleen McLean ◽

J. L. Reid

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Blood Pressure Control ◽

Normal Subjects ◽

Pressure Control ◽

Endogenous Opioids ◽

Plasma Noradrenaline ◽

Head Up Tilt ◽

Blind Manner

1. Two studies were performed to elucidate the role of opioids in blood pressure control in man. 2. Study 1: nine normal subjects, 18–32 years, received in a randomized single blind manner, volume matched infusions of a Met-enkephalin analogue (DAMME) 0.5 mg, naloxone 0.2 mg/kg or saline. Blood pressure, heart rate and plasma noradrenaline were determined supine and after a 5 min, 70° head-up tilt at 0, 3/4, 2, 3, 4, 5 and 6 h. 3. Study 2: seven subjects, after baseline recordings of blood pressure and heart rate received six incremental infusions of sodium nitroprusside, 1.5–7.5 μg min−1 kg−1. They then received DAMME or naloxone and the nitroprusside infusions were repeated between 3 and 4 h. There was a significant linear relationship between fall in mean arterial pressure and rise in heart rate in each case and the slope was used as an index of baroreflex sensitivity. 4. Neither naloxone nor DAMME influenced supine blood pressure or heart rate. Blood pressure after head-up tilt was significantly (analysis of variance) decreased by DAMME for up to 5 h but not by naloxone, the effect being most marked at 3 h: systolic (mean ± sd), placebo 110 ± 6, naloxone 106 ± 10, DAMME 96 ± 16 (P< 0.02); diastolic (mean ± sd), placebo 78 ± 7, naloxone 79 ± 5, DAMME 67 ± 8 (P < 0.01). The increases in heart rate and plasma noradrenaline on tilting after DAMME were not significantly different from values with placebo or naloxone. The 3 h values for heart rate were: placebo 87 ± 16, naloxone 88 ± 19, DAMME 89 ± 23 (P > 0.1); for plasma noradrenaline (nmol/l): placebo 6.0 ± 2.2, naloxone 5.8 ± 1.9, DAMME 6.0 ± 1.9 (P > 0.1). 5. Naloxone significantly increased the slope (beats per min/mmHg) of the regression relationship from a mean of 1.8 ± 0.07 to 3.0 ± 1.3 (P < 0.05), and DAMME reduced the slope from 2.7 ± 1.7 to 1.2 ± 0.5 (P < 0.05). 6. We conclude that endogenous opioids modulate baroreflex function in man.

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