Vasopressin-Induced Increase in Total Peripheral Resistance in Deoxycorticosterone Acetate Hypertensive Rats is Buffered by the Baroreceptor Reflex

1981 ◽  
Vol 61 (s7) ◽  
pp. 153s-156s ◽  
Author(s):  
W. Rascher ◽  
R. E. Lang ◽  
M. Taubitz ◽  
H. Meffle ◽  
TH. Unger ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Baroreceptor Reflex ◽  
Hypertensive Rats ◽  
Control Groups ◽  
Deoxycorticosterone Acetate ◽  
Normotensive Control

1. The role of arginine-vasopressin (AVP) in the maintenance of high blood pressure in rats with deoxycorticosterone acetate (DOCA) hypertension was investigated. 2. Plasma concentrations of AVP were significantly elevated in DOCA hypertensive rats compared with normotensive control rats, whether or not they received 1% sodium chloride solution or demineralized water to drink. 3. The specific antagonist of the vasopressor response to AVP, d(CH2)5VDAVP (100 μg/kg intravenously), significantly increased cardiac output and decreased total peripheral resistance, but had no effect on mean arterial pressure in DOCA hypertensive rats. No changes of mean arterial pressure, cardiac output and total peripheral resistance were observed in the normotensive control groups after d(CH2)5VDAVP. 4. After sino-aortic baroreceptor deafferentation, d(CH2)5VDAVP decreased mean arterial pressure in DOCA—salt hypertensive rats, but not in the control groups. 5. It is concluded that elevated circulating AVP causes vasoconstriction in DOCA hypertensive rats. The AVP-induced increase in total peripheral resistance is counter-regulated by an activation of the baroreceptor reflex and subsequent reduction in cardiac output.

Hemodynamic studies in DOCA-salt hypertensive rats after opening of an arteriovenous fistula

1992 ◽  
Vol 262 (6) ◽  
pp. H1802-H1808 ◽  
Author(s):  
M. Huang ◽  
R. L. Hester ◽  
A. C. Guyton ◽  
R. A. Norman
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Cardiovascular Responses ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Hypertensive Rats

We determined the cardiovascular responses in normal and deoxycorticosterone acetate (DOCA)-salt hypertensive rats with reduced total peripheral resistance due to an arteriovenous (a-v) fistula. Animals were divided into four groups: control, fistula, DOCA-salt, and DOCA-salt fistula. The fistula was made by anastomosing the aorta and vena cava below the renal arteries. Four weeks after the creation of the fistula both DOCA-salt and DOCA-salt fistula animals received DOCA and salt for 6–8 wk. At the end of 10–12 wk we measured mean arterial pressure, cardiac output, tissue flows, and right atrial pressure. Flow measurements using radioactive microspheres were made in anesthetized animals. Cardiac index (CI) was 202% higher in the fistula group than in the control animals and 165% higher in the DOCA-salt fistula than in the DOCA-salt animals. There was no difference in cardiac output between the control and DOCA-salt animals. The increase in cardiac output was due to the fistula flow as evidenced by a significant increase in the number of microspheres in the lung. Mean arterial pressure was 115 +/- 4 mmHg (control) and 108 +/- 5 mmHg (fistula) in non-DOCA rats but increased in both DOCA groups, 159 +/- 3 mmHg (DOCA-salt) and 145 +/- 5 mmHg (DOCA-salt fistula). Right atrial pressure was increased above control in both fistula animals but was normal in DOCA-salt animals. Total peripheral resistance (TPR) was higher than control in DOCA-salt animals, but TPR in both the fistula and DOCA-salt fistula animals was lower than control.(ABSTRACT TRUNCATED AT 250 WORDS)

Haemodynamic Alterations after Reversal of Renal Hypertension in Rats

1979 ◽  
Vol 57 (s5) ◽  
pp. 15s-17s ◽  
Author(s):  
Margareta Hallbäck-Nordlander ◽  
E. Noresson ◽  
Y. Lundgren
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Smooth Muscle ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Vascular Changes ◽  
Hypertensive Rats ◽  
Renal Hypertensive Rats

1. Cardiac output, heart rate and mean arterial pressure were determined in two-kidney Goldblatt hypertensive rats of 4 weeks' duration, in matched normotensive controls and in declipped renal hypertensive rats 2 h-28 days after renal artery declipping. 2. After declipping mean pressure fell rapidly due to a corresponding reduction in total peripheral resistance, this being normalized after 1 day. Cardiac output and heart rate remained initially unchanged, but 1 day after declipping the former was significantly increased compared with output in renal hypertensive rats. 3. The initial normalization of total peripheral resistance must be ascribed to a subnormal vascular smooth muscle tone. The reason is that the hypertensive structural vascular changes are not yet significantly reduced and their presence implies an elevated flow resistance, even when vascular smooth muscle activity equals that in normotension. 4. This considerable ‘overshoot’ in vascular relaxation and lack of reflexogenic tachycardia, despite resetting of baroreceptors, suggest that peripheral as well as central mechanisms contribute to the rapid normalization of mean arterial pressure in two-kidney Goldblatt hypertension in rats, later stabilized by reversal of structural vascular changes.

Baroreceptor-mediated compensation for hemodynamic effects of positive end-expiratory pressure

1999 ◽  
Vol 86 (1) ◽  
pp. 285-293 ◽  
Author(s):  
Stephen S. Blevins ◽  
Martha J. Connolly ◽  
Drew E. Carlson
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Systemic Arterial Pressure ◽  
Baroreceptor Reflex ◽  
Right Atrial ◽  
Positive End Expiratory Pressure ◽  
Carotid Baroreceptor ◽  
The Right

The roles of the carotid arterial baroreceptor reflex and of vagally mediated mechanisms during positive end-expiratory pressure (PEEP) were determined in pentobarbital-anesthetized dogs with isolated carotid sinuses. Spontaneously breathing dogs were placed on PEEP (5–10 cmH2O) with the carotid sinus pressure set to the systemic arterial pressure (with feedback) or to a constant pressure (no feedback). Right atrial volume was measured with a conductance catheter. With carotid baroreceptor feedback before bilateral cervical vagotomy, total peripheral resistance increased ( P < 0.01) and mean arterial pressure decreased (−9.8 ± 4.3 mmHg) in response to PEEP. With no feedback after vagotomy, mean arterial pressure decreased to a greater extent (−45 ± 6 mmHg, P < 0.01), and total peripheral resistance decreased ( P < 0.05) in response to PEEP. In contrast, cardiac index decreased similarly during PEEP ( P < 0.01) for all baroreceptor and vagal inputs. This response comprised a decrease in the passive phase of right ventricular filling ( P< 0.01) that was not matched by the estimated increase in active right atrial output. Although the carotid baroreceptor reflex and vagally mediated mechanisms elicit vasoconstriction to compensate for the effects of PEEP on the arterial pressure, these processes fail to defend cardiac output because of the profound effect of PEEP on the passive filling of the right ventricle.

Effects of phenoxybenzamine, metoprolol, captopril, and meclofenamate on cardiovascular function in deoxycorticosterone acetate hypertensive Yucatan miniature swine

1983 ◽  
Vol 61 (2) ◽  
pp. 149-153 ◽  
Author(s):  
Charles D. Ciccone ◽  
Edward J. Zambraski
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Arterial Pressure ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Response Curves ◽  
Miniature Swine ◽  
Deoxycorticosterone Acetate ◽  
Adrenergic Activity ◽  
Conscious Animals

Eight adult Yucatan miniature swine were implanted with deoxycorticosterone acetate (DOCA) impregnated silicone strips (100 mg∙kg−1). After 16 weeks of DOCA treatment mean arterial pressure (MAP) increased to 183 ± 4 mmHg (1 mmHg = 133.322 Pa). In four normal animals arterial pressure was 126 ± 8 mmHg. The increase in MAP in the DOCA animalas was due to an elevated total peripheral resistance (TPR) with cardiac output remaining normal. In tests with conscious animals, phenoxybenzamine (1 mg∙kg−1) significantly decreased arterial pressure via a selective decrease in TPR. Neither meclofenamate, metoprolol, nor captopril affected MAP in these DOCA hypertensive animals. Dose–response curves to exogenous norepinephrine and angiotensin II revealed that the DOCA animals had an increased pressor sensitivity to both of these agents. These data suggest that in the DOCA hypertensive Yucatan swine an increase in alpha adrenergic activity and (or) an increase in smooth muscle responsiveness to circulating catecholamines is responsible for the increase in blood pressure as a result of an increase in total peripheral resistance.

scholarly journals Abnormal cardiovascular response to nitroglycerin in migraine

Cephalalgia ◽  
2019 ◽  
Vol 40 (3) ◽  
pp. 266-277
Author(s):  
Willebrordus PJ van Oosterhout ◽  
Guus G Schoonman ◽  
Dirk P Saal ◽  
Roland D Thijs ◽  
Michel D Ferrari ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Total Peripheral Resistance ◽  
Cardiovascular Response ◽  
Peripheral Resistance ◽  
Cardiovascular Responses ◽  
Initial Increase

Introduction Migraine and vasovagal syncope are comorbid conditions that may share part of their pathophysiology through autonomic control of the systemic circulation. Nitroglycerin can trigger both syncope and migraine attacks, suggesting enhanced systemic sensitivity in migraine. We aimed to determine the cardiovascular responses to nitroglycerin in migraine. Methods In 16 women with migraine without aura and 10 age- and gender-matched controls without headache, intravenous nitroglycerin (0.5 µg·kg−1·min−1) was administered. Finger photoplethysmography continuously assessed cardiovascular parameters (mean arterial pressure, heart rate, cardiac output, stroke volume and total peripheral resistance) before, during and after nitroglycerin infusion. Results Nitroglycerin provoked a migraine-like attack in 13/16 (81.2%) migraineurs but not in controls ( p = .0001). No syncope was provoked. Migraineurs who later developed a migraine-like attack showed different responses in all parameters vs. controls (all p < .001): The decreases in cardiac output and stroke volume were more rapid and longer lasting, heart rate increased, mean arterial pressure and total peripheral resistance were higher and decreased steeply after an initial increase. Discussion Migraineurs who developed a migraine-like attack in response to nitroglycerin showed stronger systemic cardiovascular responses compared to non-headache controls. The stronger systemic cardiovascular responses in migraine suggest increased systemic sensitivity to vasodilators, possibly due to insufficient autonomic compensatory mechanisms.

Cardiovascular Effects of Moxibustion at Jen Chung (Go-26) during Halothane Anesthesia in Dogs

1975 ◽  
Vol 03 (03) ◽  
pp. 245-261 ◽  
Author(s):  
Do Chil Lee ◽  
Myung O. Lee ◽  
Donald H. Clifford
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Total Peripheral Resistance ◽  
Venous Pressure ◽  
Peripheral Resistance ◽  
Cardiovascular Effects ◽  
Halothane Anesthesia

The cardiovascular effects of moxibustion at Jen Chung (Go-26) in 10 dogs under halothane anesthesia were compared to 5 dogs under halothane anesthesia without moxibustion and 5 dogs under halothane anesthesia in which moxibustion was effected at a neutral or non-acupuncture site. Cardiac output, stroke volume, heart rate, mean arterial pressure, central venous pressure, total peripheral resistance, pH, PaCO2, PaO2 and base deficit were measured over a two-hour period. A significant increase in cardiac output and stroke volume and a significant decrease in the total peripheral resistance were observed in the group which was stimulated by moxibustion at Jen Chun (Go-26). Heart rate, mean arterial pressure and pulse pressure were significantly increase during the early part of the two-hour period in the same group. The cardiovascular effects of moxibustion at Jen Chung (Go-26) which were observed at the end of the two hours were also present in two dogs in which measurements were continued for two additional hours.

Hemodynamic monitoring for 24 h in unanesthetized rats

1987 ◽  
Vol 253 (6) ◽  
pp. H1335-H1341 ◽  
Author(s):  
T. L. Smith ◽  
T. G. Coleman ◽  
K. A. Stanek ◽  
W. R. Murphy
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Cardiac Index ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Diurnal Variation ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Total Peripheral Resistance Index

A new technique is described that allows minute-to-minute recordings of cardiac output and arterial pressure in unanesthetized rats for periods of 24 h and longer. Rats were instrumented with electromagnetic flow probes and arterial catheters. An electrical and hydraulic swivel was interposed between the rat and recording apparatus to allow free range of movement. Data were collected and analyzed once each minute by computer. Average 24-h values (mean +/- SD) for the following hemodynamic variables were determined in eight rats [expressed where appropriate as a function of body weight (BW)]: cardiac output (98.1 +/- 14.7 ml/min), cardiac index (29.2 +/- 4.4 ml.min-1.100 g BW-1), mean arterial pressure (92.5 +/- 7.8 mmHg), heart rate (347 +/- 45 beats/min), peak aortic flow (403 +/- 32 ml/min), stroke volume (282 +/- 26 microliters), stroke volume index (84.4 +/- 8.1 microliters/100 g BW), and total peripheral resistance index (3.26 +/- 0.46 mmHg.ml-1.min.100 g BW). These results provide a data base of hemodynamic values for unanesthetized adult, Sprague-Dawley male rats, which has not been previously available. In addition, cardiac index, mean arterial pressure, and total peripheral resistance index demonstrated diurnal variation. Diurnal variation contributed substantially to the overall variance observed within these variables. Hourly variance was also substantial and indicates the use of continuous recordings for short-term experiments.

Sympathetic and Parasympathetic Components of Reflex Cardiostimulation during Vasodilator Treatment of Hypertension

1978 ◽  
Vol 55 (s4) ◽  
pp. 329s-332s ◽  
Author(s):  
A. J. Man in 't Veld ◽  
G. J. Wenting ◽  
R. P. Verhoeven ◽  
M. A. D. H. Schalekamp
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Hypertensive Patients ◽  
Treatment Of Hypertension ◽  
Before And After ◽  
Vasodilator Treatment

1. Haemodynamic responses to diazoxide (300 mg intravenously) were studied in 15 hypertensive patients before and after chronic β-adrenoreceptor blockade by 320 mg of propranolol daily. After diazoxide alone, mean arterial pressure and total peripheral resistance were lowered by 24 ± 3 and 35 ± 5% (mean ± sem) respectively. Cardiac output and heart rate rose by 25 ± 9 and 21 ± 3%. During β-adrenoreceptor blockade, the percentage changes of mean arterial pressure, heart rate, cardiac output and total peripheral resistance after vasodilatation were not significantly different from those after diazoxide alone. 2. Atropine, 0·04 mg/kg body weight, was given to 12 hypertensive patients chronically treated with β-adrenoreceptor blockade, before acute vasodilatation by diazoxide. Diazoxide caused no increase in heart rate after combined β-adrenoreceptor and parasympathetic blockade. However, cardiac output rose by 14 ± 5%. 3. We conclude that withdrawal of parasympathetic tone is an important determinant of circulatory homeostasis after acute vasodilatation during β-adrenoreceptor blockade.

Cardiac output mediates the antihypertensive effect of vasopressin in spontaneous hypertension

1996 ◽  
Vol 271 (5) ◽  
pp. H1728-H1733
Author(s):  
S. Balakrishnan ◽  
J. R. McNeill
Keyword(s):  
Cardiac Output ◽  
Arterial Pressure ◽  
Total Peripheral Resistance ◽  
Time Course ◽  
Antihypertensive Effect ◽  
Peripheral Resistance ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Time Flow ◽  
Wistar Kyoto

The contribution of cardiac output and total peripheral resistance to the fall in arterial pressure that follows cessation of a 3-h intravenous infusion of arginine vasopressin (AVP; 20 ng.kg-1.min-1) was studied in conscious spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats instrumented with radiotelemetric probes for recording of blood pressure and ultrasonic transit-time flow probes for measuring cardiac output. Cessation of a 3-h infusion of AVP resulted in a significant decrease in arterial pressure in SHR (14-17 mmHg below preinfusion control levels) but not in WKY or in vehicle-treated controls. The fall in pressure persisted for several days. The fall in pressure was associated with a large decrease in cardiac output of 22 +/- 2 ml/min below control levels in SHR, and the time course of the cardiac output response over several days approximated the time course of the pressure response. By contrast, total peripheral resistance remained elevated for some time on withdrawal of the AVP infusion. We conclude that the withdrawal-induced antihypertensive phenomenon in SHR is mediated by a fall in cardiac output and not by a decline in total peripheral resistance.

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