Quantitative assay and disappearance rate of circulating renin

1964 ◽  
Vol 206 (6) ◽  
pp. 1361-1364 ◽  
Author(s):  
G. Schaechtelin ◽  
D. Regoli ◽  
F. Gross
Keyword(s):  
Blood Pressure ◽  
Blood Pressure Response ◽  
Pressure Response ◽  
Pressure Increase ◽  
Disappearance Rate ◽  
Hypertensive Rats ◽  
Contralateral Kidney ◽  
Blood Pressure Increase ◽  
Hypertensive Animal ◽  
Renal Hypertensive Rats

In isovolemic cross-circulation experiments, a nephrectomized donor rat, into which various doses of hog renin were injected, was connected to a nephrectomized indicator rat. The blood pressure increase thus produced in the indicator rat was compared with the blood pressure response obtained during cross circulation using either intact normotensive or renal hypertensive rats as donor animals. An exponential dose-response relationship was found between hog renin injected into a nephrectomized donor and the blood pressure increase of the indicator rat. Using the cross-circulation technique, the disappearance rate of endogenous reninlike material in the blood of donor animals and of exogenous renin injected into nephrectomized donor animals was examined. If an intact normotensive animal or a unilaterally nephrectomized hypertensive animal is totally nephrectomized, reninlike material disappears from the blood within 1 hr. In renal hypertensive rats with an untouched contralateral kidney which have a higher concentration of reninlike material in the blood, it takes about twice the normal time until reninlike material disappears from the blood after nephrectomy. The increased and prolonged blood pressure response of the nephrectomized animal to renin is not connected with a prolonged persistence of renin in the blood.

Hormonally maintained high blood pressure following adrenalectomy in rats with adrenal-regeneration hypertension and its possible significance in the etiology of that disorder

1968 ◽  
Vol 46 (2) ◽  
pp. 269-274 ◽  
Author(s):  
C. E. Hall ◽  
O. B. Holland ◽  
O. Hall
Keyword(s):  
Blood Pressure ◽  
High Blood Pressure ◽  
Blood Pressure Response ◽  
Pressure Rise ◽  
Pressure Response ◽  
Pressure Increase ◽  
Blood Pressure Increase ◽  
Blood Pressure Rise ◽  
Thymus Involution ◽  
Adrenalectomized Rats

Rats were caused to develop adrenal-regeneration hypertension, and attempts were made to reproduce in them after adrenalectomy the same rate of blood pressure rise as occurred in animals allowed to retain enucleated adrenals, by using aldosterone, corticosterone, or a mixture of the two. Corticosterone at 2.5 mg/day caused a somewhat greater rate of blood pressure increase than occurred in rats retaining regenerating glands, but whereas the latter did not manifest thymus involution, hormone-treated animals did. At 1 mg/day there was a drop in blood pressure following adrenalectomy in rats with adrenal-regeneration hypertension, although not always to normotensive levels, and the characteristic hypotension of adrenalectomized rats was prevented. Rats given 100 μg/day of aldosterone following adrenalectomy maintained a continued rise of blood pressure, the rate not differing significantly from that seen in rats with continuing adrenal-regeneration hypertension. Such rats did not display thymus involution, and the blood pressure response was no greater when 1 mg/day of corticosterone was added to the regimen. It is concluded that if the profile of hypertension and failure to cause thymus involution are valid criteria for establishing the identity of the hormone(s) which cause adrenal-regeneration hypertension, aldosterone appears to qualify. Some reasons for doubting the reliability of these criteria and some of the difficulties encountered in attempting to compare quantitatively the effects of endogenously secreted hormone with exogenously administered hormone are given.

Blood Pressure Response to Physical Exercise in Healthy Adolescents and Adolescents with Insulin-Dependent Diabetes Mellitus

1994 ◽  
Vol 86 (4) ◽  
pp. 425-432 ◽  
Author(s):  
H. Nordgren ◽  
U. Freyschuss ◽  
B. Persson
Keyword(s):  
Diabetes Mellitus ◽  
Blood Pressure ◽  
Body Weight ◽  
Metabolic Control ◽  
Blood Pressure Response ◽  
Insulin Dependent Diabetes Mellitus ◽  
Pressure Response ◽  
Pressure Increase ◽  
Dependent Diabetes Mellitus ◽  
Insulin Dependent

1. Reference values for systolic blood pressure during exercise are provided for 88 healthy adolescents (12–22 years of age) of both sexes. Data were related to oxygen uptake, heart rate, blood lactate concentration, rate of perceived exertion, age, sex, body size and physcial fitness. 2. The same variables were measured in 55 adolescents of both sexes with insulin-dependent diabetes mellitus of about 12 years duration and were analysed with respect to the healthy control group, to degree of metabolic control and to late diabetic complications. 3. In healthy adolescents the pressure response was not related to sex or age. When compared with control subjects diabetic patients had a higher diastolic blood pressure at rest and a more marked blood pressure increase, 23 versus 19 mmHg W−1 kg−1 body weight, during exercise with no sex difference. The blood pressure rise was not related to metabolic control, glomerular hyperfiltration or physical fitness. 4. Prolonged exercise tests were no more informative regarding the blood pressure response to exercise than the stepwise increased load test. Analysing the blood pressure increase versus relative work load (W/kg body weight) during exercise reveals blood pressure differences otherwise not noted. A diabetic patient with blood pressure above the 97.5% confidence limit during exercise seems to have a higher risk of developing incipient nephropathy 5 years later.

Antidiuretic and pressor actions of vasopressin in age-dependent DOCA-salt hypertension

1989 ◽  
Vol 256 (1) ◽  
pp. R138-R145 ◽  
Author(s):  
J. Zicha ◽  
J. Kunes ◽  
M. Lebl ◽  
I. Pohlova ◽  
J. Slaninova ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Pressure Response ◽  
Body Fluids ◽  
Pressure Response ◽  
Fluid Volume ◽  
Brattleboro Rats ◽  
Hypertensive Rats ◽  
Salt Treatment ◽  
Age Dependent ◽  
Salt Hypertension

The role of antidiuretic and pressor effects of vasopressin (VP) in deoxycorticosterone acetate (DOCA)-salt hypertension was studied in young and adult Brattleboro rats. The antidiuretic VP action was a necessary prerequisite for the development of severe DOCA-salt hypertension. The insufficient expansion of extracellular fluid volume in DOCA-salt-treated VP-deficient (DI) rats was associated with the attenuation of their hypertensive response, although they had highly increased blood volume and extracellular sodium. Chronic [deamino]-D-arginine vasopressin supplementation that restored volume and distribution of body fluids in DI rats permitted the full development of DOCA-salt hypertension. Blood pressure response to DOCA-salt treatment was always greater in young than in adult Brattleboro rats (even in animals lacking pressor or both VP effects). In animals in which antidiuretic VP effects were present, the pattern of body fluid response to DOCA-salt treatment was also age dependent. There was a tendency to intravascular expansion in young hypertensive rats, whereas an increase of interstitial fluid volume was found in adult animals. The elimination of VP pressor action lowered systemic resistance much more in adult than in young hypertensive rats. We conclude that 1) in adult but not in young rats antidiuretic VP effects are essential for the occurrence of blood pressure response to DOCA-salt treatment, 2) the restoration of body fluids due to antidiuretic VP action enables the development of hypertension in both age groups of DI rats, and 3) pressor VP effects contribute to the maintenance of hypertension, especially in adult animals.

The Vicious Circle in Acute Malignant Hypertension of Rats

1973 ◽  
Vol 45 (s1) ◽  
pp. 251s-255s ◽  
Author(s):  
G. Dauda ◽  
J. Möhring ◽  
K. G. Hofbauer ◽  
E. Homsy ◽  
Ulrike Miksche ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Renal Hypertension ◽  
Plasma Renin ◽  
Malignant Hypertension ◽  
Hypertensive Rats ◽  
Marked Rise ◽  
Contralateral Kidney ◽  
Renal Hypertensive Rats ◽  
Malignant Nephrosclerosis ◽  
Drinking Fluid

1. In renal hypertensive rats, increase in blood pressure above 180 mmHg may induce sodium and water loss, reduced growth rate, elevated haematocrit, a marked rise in plasma renin concentration, an increase in renin extractable from the clamped and the contralateral kidney and malignant nephrosclerosis of the contralateral kidney. These symptoms characterize the malignant phase of renal hypertension in rats. 2. When water was given as drinking fluid, ten of eighteen rats developed signs of malignant hypertension and malignant nephrosclerosis within 3–4 weeks. Administration of 0.9% saline instead of water induced higher blood-pressure levels, but only five of eighteen rats showed malignant nephrosclerosis. When drinking fluid was changed from water to saline shortly before or shortly after the onset of malignant hypertension, the condition improved, and in only one of twelve rats was malignant nephrosclerosis observed. 3. It is concluded that in renal hypertensive rats sodium supplements may improve or prevent signs of malignant hypertension and the development of malignant nephrosclerosis.

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