Effect of 1 Year's Therapy in Essential Hypertension on Systemic Haemodynamics Studied before and after ‘Total’ Autonomic Blockade

1979 ◽  
Vol 57 (s5) ◽  
pp. 11s-13s ◽  
Author(s):  
G. L. Jennings ◽  
P. I. Korner ◽  
M. D. Esler
Keyword(s):  
Essential Hypertension ◽  
Blood Pressure Reduction ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Antihypertensive Drug Therapy ◽  
Complete Restoration ◽  
Before And After ◽  
Autonomic Blockade ◽  
Normotensive Subjects ◽  
Total Peripheral Resistance Index

1. The haemodynamics of ten patients with essential hypertension were studied before treatment (study 1) and again 1 week after cessation of 1 year's antihypertensive drug therapy (study 2). On each occasion measurements of mean arterial pressure (MAP), cardiac index (CI) and total peripheral resistance index (TPRI) were made before and after ‘total’ pharmacological autonomic blockade (with intravenous propranolol, atropine, phentolamine and clonidine); measurements after ‘total’ autonomic blockade were used to assess the magnitude of the ‘non-autonomic’ component of TPRI, which reflects humoral or structural alterations in the vasculature. 2. The findings before ‘total’ autonomic blockade during study 2 showed that MAP was 18 ± 8 mmHg below the value (135 mmHg) observed during study 1 before treatment, and TPRI had fallen by 33% (P < 0·05) and CI had increased by 23% (P < 0·05). 3. After ‘total’ autonomic blockade the differences in the ‘non-autonomic’ components of the different variables were similar, with ‘non-autonomic’ MAP 14 ± 4 mmHg lower in study 2, TPRI 42% lower (P < 0·005) and CI 28% higher. The value in ‘non-autonomic’ TPRI was now the same as values previously observed in normotensive subjects. 4. We conclude that after 1 year's successful treatment there is complete restoration of ‘non-autonomic’ TPRI as a secondary consequence of the blood pressure reduction.

Proximal and Distal Tubular Reabsorption during Isotonic Volume Expansion in Patients with Essential Hypertension as Estimated by Means of Combined Lithium and 51Cr-Labelled EDTA Clearance

1982 ◽  
Vol 63 (s8) ◽  
pp. 219s-221s ◽  
Author(s):  
N.-H. Holstein-Rathlou ◽  
U. G. Svendsen ◽  
P. P. Leyssac
Keyword(s):  
Essential Hypertension ◽  
Significant Rise ◽  
Tubular Reabsorption ◽  
Sodium Reabsorption ◽  
Absolute Rate ◽  
Hypertensive Patients ◽  
Volume Load ◽  
Before And After ◽  
Normotensive Subjects ◽  
Normotensive Control

1. Ten patients with essential hypertension and ten normotensive control subjects were investigated before and after an isotonic volume load. 2. The increases in the clearances of lithium and of sodium were greater in the hypertensive than in the normotensive subjects (P < 0.05). The fractional increases showed a positive correlation (rs = 0.68, P < 0.05) in the hypertensive patients. 3. An increase in glomerular filtration rate in the hypertensive patients correlated positively with the increase in proximal output (rs = 0.70, P < 0.05), but did not correlate with the change in sodium excretion. 4. The exaggerated natriuresis was accompanied by a significant rise in the absolute rate of sodium reabsorption in the distal segments, but distal fractional reabsorption decreased. 5. It is concluded that the exaggerated natriuresis can be accounted for by an increase in the proximal output of sodium and water.

Effect of prednisone on digital vascular reactivity in normotensive and hypertensive subjects

1961 ◽  
Vol 16 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Milton Mendlowitz ◽  
Nosrat Naftchi ◽  
Herbert L. Weinreb ◽  
Stanley E. Gitlow
Keyword(s):  
Essential Hypertension ◽  
Intravenous Injection ◽  
Vascular Reactivity ◽  
Oral Prednisone ◽  
Moderate Increase ◽  
Single Intravenous Injection ◽  
Hypertensive Group ◽  
Before And After ◽  
Group A ◽  
Normotensive Subjects

Reactivity to L-norepinephrine (NE) was studied in the digital circulation of normotensive and hypertensive subjects before and after the administration of glucocorticosteroids. After 1 week of oral prednisone administration (30 mg daily) NE reactivity was higher in some, but not all, the normotensive subjects and remained substantially unchanged in the hypertensive group. A single intravenous injection of prednisolone (100 mg) resulted in a moderate increase in NE reactivity in the normotensive but not in the hypertensive subjects. After 3 weeks of oral prednisone administration (30 mg daily), NE reactivity was doubled or trebled in most normotensive subjects but remained unchanged in the patients with essential hypertension. These observations suggest that the effect of glucocorticosteroids on NE reactivity in normotensive subjects is chemical and that this effect is absent or modified in patients with essential hypertension. Submitted on December 28, 1959

Hypertension in the Elderly: Haemodynamic, Fluid Volume and Endocrine Findings

1981 ◽  
Vol 61 (s7) ◽  
pp. 393s-394s ◽  
Author(s):  
F. H. Messerli ◽  
L. B. Glade ◽  
G. R. Dreslinski ◽  
F. G. Dunn ◽  
E. Reisin ◽  
...  
Keyword(s):  
Essential Hypertension ◽  
Peripheral Resistance ◽  
Plasma Renin ◽  
The Elderly ◽  
Fluid Volume ◽  
Intravascular Volume ◽  
Pathophysiological Process ◽  
Normotensive Subjects ◽  
Lower Cardiac Output ◽  
Noradrenaline Levels

1. Systemic and renal haemodynamics, intravascular volume, circulating catecholamines and plasma renin activity were measured in 18 patients with established essential hypertension who were older than 60 years of age. Each patient was matched with respect to mean arterial pressure, body surface area, race and sex with a patient that was younger than 42 years of age. 2. When compared with the younger group, elderly patients had a lower cardiac output, impaired myocardial reserve, lesser aortic elasticity, higher total peripheral resistance, more contracted intravascular volume and higher circulating noradrenaline levels. 3. Similar effects of age, although less pronounced, have been reported in normotensive subjects. We conclude that essential hypertension is a pathophysiological process that seems to accelerate the natural physiological haemodynamic, fluid volume and endocrine processes of aging.

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.

Neurogenic Participation in Essential and Renovascular Hypertension Assessed by Acute Ganglionic Blockade: Correlation with Haemodynamic Indices and Intravascular Volume

1973 ◽  
Vol 44 (3) ◽  
pp. 197-212 ◽  
Author(s):  
R. C. Tarazi ◽  
Harriet P. Dustan
Keyword(s):  
Essential Hypertension ◽  
Renovascular Hypertension ◽  
Peripheral Resistance ◽  
Arterial Stenosis ◽  
Intravascular Volume ◽  
Physiological Factors ◽  
Depressor Response ◽  
Different Types ◽  
Normotensive Subjects ◽  
Pressure Resistance

1. Neurogenic activity at rest was estimated from the immediate depressor response to intravenously administered trimetaphan in two groups of untreated hypertensive patients (thirty with essential hypertension and twenty with renal arterial stenosis). Responses were correlated with simultaneously determined haemodynamic functions and intravascular volume. 2. The two groups did not differ significantly in degree of response but the pattern of its correlations was different. In essential hypertension, the depressor response correlated directly with control total peripheral resistance (P < 0.005) and diastolic arterial pressure (P < 0.025) and inversely with blood volume (P < 0.02); data from seven age-matched normotensive subjects fell along the same regression lines. In renovascular hypertension, on the other hand, the response did not correlate with either pressure, resistance or volume. The results suggest the interference in renovascular hypertension of a factor or factors not evident in essential hypertension. Further, this approach indicates that different types of hypertension may differ more by the pattern in which physiological factors interrelate than by a disturbance of a single factor alone.

scholarly journals Thyrotropin releasing hormone in hypovolemia: a hemodynamic evaluation in the rat

1986 ◽  
Vol 250 (6) ◽  
pp. H1093-H1101 ◽  
Author(s):  
A. L. Siren ◽  
E. Powell ◽  
G. Feuerstein
Keyword(s):  
Renal Artery ◽  
Regional Blood Flow ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Thyrotropin Releasing Hormone ◽  
Pulsed Doppler ◽  
Conscious Rat ◽  
Releasing Hormone ◽  
Total Peripheral Resistance Index ◽  
Hypovolemic Hypotension

In the present study the effects of thyrotropin releasing hormone (TRH) and its stable analogue, CG3703, on cardiac output (thermodilution, Cardiomax) and regional blood flow (BF; directional pulsed Doppler technique) were investigated in hypovolemic hypotension in the rat. In urethan-anesthetized rats TRH (0.5 or 2 mg/kg ia) or CG3703 (0.05 or 0.5 mg/kg ia) reversed the bleeding (27% of the blood volume)-induced decreases in mean arterial pressure (MAP) and cardiac index (CI) and increased the heart rate (HR) and total peripheral resistance index (TPRI) in a dose-related manner. In the conscious rat exposed to a 45% hemorrhage, CG3703 (0.5 mg/kg ia) significantly raised MAP, HR, and TPRI with maximum changes of +67 +/- 6 (SE) mmHg, +123 +/- 30 beats/min, and +101 +/- 2%, respectively, CG3703 (0.5 mg/kg ia) also further enhanced the hemorrhage-induced reduction of hindquarter, mesenteric, and renal BF. The changes in BF in saline-treated vs. CG3703-treated rats 2 h after the bleeding were -32 +/- 6 vs. -55 +/- 6% (P less than 0.001) in hindquarter, -9 +/- 8 vs. -61 +/- 11% (P less than 0.001) in mesenteric, and -2 +/- 9 vs. -33 +/- 9% (P less than 0.01) in the renal artery; the changes in vascular resistance +30 +/- 7 vs. +309 +/- 167% (P less than 0.001) in hindquarter, -4 +/- 8 vs. +349 +/- 244% in the mesenteric, and -10 +/- 9 vs. +80 +/- 10% (P less than 0.01) in the renal artery. The survival rate after the 45% hemorrhage was significantly reduced by both TRH and CG3703.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced vascular effects of the Ca2+ channel agonist Bay K 8644 in pregnant rabbits

2002 ◽  
Vol 282 (4) ◽  
pp. R952-R959 ◽  
Author(s):  
Rocco Venuto ◽  
Gail Brown ◽  
Marion Schoenl ◽  
György Losonczy
Keyword(s):  
Peripheral Resistance ◽  
Resistance Index ◽  
Bay K 8644 ◽  
Vascular Effects ◽  
Pressor Responses ◽  
Voltage Dependent ◽  
Cardiac Output Index ◽  
Voltage Dependent Calcium Channels ◽  
Fractional Increase ◽  
Total Peripheral Resistance Index

Hemodynamic studies were performed to determine if blunting of vascular pressor responsiveness to vasoconstrictors during pregnancy may be due to impaired L-type voltage-dependent calcium channels (L-VDCC). Bay K 8644 (BAY), an L-VDCC agonist, was infused in pregnant and nonpregnant anesthetized rabbits (10, 20, 40, and 60 μg/kg) and pregnant and nonpregnant conscious, chronically instrumented (conscious) rabbits (10, 25, and 50 μg/kg). BAY infusions resulted in greater elevation of mean arterial pressure in both anesthetized pregnant ( n = 6) vs. nonpregnant ( n = 6) ( P < 0.05) and conscious pregnant ( n = 10) vs. nonpregnant ( n = 10) rabbits ( P < 0.05). Fractional increase over baseline of total peripheral resistance index was greater in pregnant (36 ± 5 to 78 ± 14%) vs. nonpregnant rabbits (14 ± 4 to 52 ± 6%) ( P< 0.02). Cardiac output index did not differ. There was a single high-affinity L-VDCC antagonist aortic binding site with similar number and affinity in pregnant ( n = 7) and nonpregnant ( n = 7) rabbits. In conclusion, stimulation of L-VDCC induces greater pressor responses in pregnant rabbits with heightened peripheral vasoconstriction. This does not appear to be due to a change in L-VDCC receptor parameters.

Peripheral chemoreceptor control of cardiovascular function at rest and during exercise in heart failure patients

2015 ◽  
Vol 118 (7) ◽  
pp. 839-848 ◽  
Author(s):  
Heather Edgell ◽  
M. Sean McMurtry ◽  
Mark J. Haykowsky ◽  
Ian Paterson ◽  
Justin A. Ezekowitz ◽  
...  
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Ejection Fraction ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Cardiovascular Control ◽  
Peripheral Chemoreceptor ◽  
Dopamine Infusion ◽  
Total Peripheral Resistance Index

Peripheral chemoreceptor activity/sensitivity is enhanced in chronic heart failure (HF), and sensitivity is linked to greater mortality. This study aimed to determine the role of the peripheral chemoreceptor in cardiovascular control at rest and during exercise in HF patients and controls. Clinically stable HF patients ( n = 11; ejection fraction: 39 ± 5%) and risk-matched controls ( n = 10; ejection fraction: 65 ± 2%) performed randomized trials with or without dopamine infusion (2 μg·min−1·kg−1) at rest and during 40% maximal voluntary contraction handgrip (HG) exercise, and a resting trial of 2 min of inspired 100% oxygen. Both dopamine and hyperoxia were used to inhibit the peripheral chemoreceptor. At rest in HF patients, dopamine decreased ventilation ( P = 0.02), decreased total peripheral resistance index ( P = 0.003), and increased cardiac and stroke indexes ( P ≤ 0.01), yet there was no effect of dopamine on these variables in controls ( P ≥ 0.7). Hyperoxia lowered ventilation in HF ( P = 0.01), but not in controls ( P = 0.9), indicating suppression of the peripheral chemoreceptors in HF. However, no decrease of total peripheral resistance index was observed in HF. As expected, HG increased heart rate, ventilation, and brachial conductance of the nonexercising arm in controls and HF patients. During dopamine infusion, there were no changes in mean arterial pressure, heart rate, or ventilation responses to HG in either group ( P ≥ 0.26); however, brachial conductance increased with dopamine in the control group ( P = 0.004), but decreased in HF ( P = 0.02). Our findings indicate that the peripheral chemoreceptor contributes to cardiovascular control at rest in HF patients and during exercise in risk-matched controls.

Central Haemodynamics and Plasma Prostaglandin E2 in Borderline and Sustained Essential Hypertensive Patients before and after Indomethacin

1981 ◽  
Vol 61 (s7) ◽  
pp. 323s-325s ◽  
Author(s):  
M. E. Safar ◽  
A. F. Hornych ◽  
J. A. Levenson ◽  
A. Ch. Simon ◽  
G. M. London ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Index ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Hypertensive Patients ◽  
Arterial Blood ◽  
Before And After ◽  
Haemodynamic Changes ◽  
Normotensive Subjects ◽  
Pg E2

1. In basal conditions, plasma arterial prostaglandin (PG) E2 was significantly increased in borderline hypertensive patients (BH) (28.5 ± 6.7 pg/ml) in comparison with sustained essential hypertensive patients (EH) (11.6 ± 3.2 pg/ml) and in comparison with control normotensive subjects (NTS) (5.8 ± 1.4 pg/ml). 2. Plasma arterial PGE2 was positively significantly correlated with cardiac index and negatively significantly correlated with total peripheral resistance in basal conditions. 3. Indomethacin induced more pronounced haemodynamic changes in borderline than in sustained hypertensive patients, with a significant increase in arterial blood pressure and total peripheral resistance and a significant decrease in stroke volume and cardiac index. 4. Indomethacin significantly decreased arterial PGE2 in borderline hypertensive patients. The decrease was less important in sustained hypertensive patients. 5. In the overall population, a significant positive correlation between arterial PGE2 concentration and cardiac index was observed before and after indomethacin treatment. 6. The study suggests an important role of PGE2 in the regulation of cardiac output (positive inotropic effect) and blood pressure of essential hypertensive patients.

Captopril Enhances Vascular and Adrenal Responsiveness to Angiotensin II in Essential Hypertension

1984 ◽  
Vol 66 (3) ◽  
pp. 299-305 ◽  
Author(s):  
Richard J. Koletsky ◽  
Murray B. Gordon ◽  
Meryl S. Leboff ◽  
Thomas J. Moore ◽  
Robert G. Dluhy ◽  
...  
Keyword(s):  
Essential Hypertension ◽  
Angiotensin Ii ◽  
Enzyme Inhibitor ◽  
Blood Pressure Response ◽  
Sodium Balance ◽  
Ang Ii ◽  
Before And After ◽  
Pah Clearance ◽  
Normotensive Subjects ◽  
Renal Vascular

1. The converting-enzyme inhibitor captopril (25–50 mg orally every 6 h for 66 h) was used to dissociate the circulating levels of angiotensin II (ANG II) from changes in sodium balance in 11 patients with normal renin essential hypertension on 10 mmol of sodium/day intake. Pressor, renal vascular and adrenal responses to graded infusions of ANG II (0.3, 1 and 3 pmol kg−1 min−1) were measured before and after captopril administration. Systemic vascular responses were assessed by measuring diastolic blood presusre (DBP), renovascular responses by measuring p-aminohippurate (PAH) clearance and adrenal responses by measuring plasma aldosterone. 2. After receiving captopril for 66 h the hypertensive subjects showed a significantly (P<0.004) enhanced blood pressure response to the infused ANG II but not to noradrenaline when compared with the response before captopril. ANG II (3 pmol kg−1 min−1) also produced a significantly (P<0.03) greater reduction in PAH clearance after (−194 ± 40 ml/min) compared with before (−104 ± 15 ml/min) captopril. These results suggest that the responsiveness to ANG II in these two target tissues is determined by the circulating ANG II level. 3. In the adrenal gland the aldosterone responses to ANG II also were significantly greater after (P < 0.01) than before captopril (increment at 3 pmol kg−1 min−1: 660 ± 88 vs 381 ± 94 pmol/l). These results are in distinct contrast with the responses previously reported for normotensive subjects and support the hypothesis that the regulation of aldosterone secretion is altered in subjects with essential hypertension.

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