Plasma Renin Activity as a Function of Age in Two New Strains of Spontaneously Hypertensive and Normotensive Rats

1976 ◽  
Vol 50 (2) ◽  
pp. 103-107 ◽  
Author(s):  
Madeleine Vincent ◽  
Jeanne Dupont ◽  
J. Sassard
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Inverse Relationship ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Fold Increase ◽  
Renin Activity ◽  
Angiotensin System ◽  
Spontaneously Hypertensive ◽  
Ether Anaesthesia

1. Strains of spontaneously hypertensive and normotensive rats were selected by repeated inbreeding. 2. Brief ether anaesthesia was shown to produce a two- to three-fold increase in plasma renin activity in both strains. 3. Plasma renin activity was significantly higher in young spontaneously hypertensive than in normotensive rats of the same age (5–7 weeks). After the ninth week plasma renin activity decreased and, at week 45, became significantly lower in hypertensive than in normotensive rats. 4. When hypertension was established a significant inverse relationship was found between plasma renin activity and systolic blood pressure in spontaneously hypertensive and in normotensive rats. 5. It seems unlikely that the renin—angiotensin system plays a major role in the maintenance of the established spontaneous hypertension in this strain. However, renin hypersecretion may be important in the early pre-hypertensive stage of genetic hypertension in rats.

What Stimulates the Renin—Angiotensin System in Rats with two-Kidney Renal Hypertension?

1983 ◽  
Vol 64 (5) ◽  
pp. 463-470
Author(s):  
Y. Takata ◽  
A. E. Doyle ◽  
M. Veroni ◽  
S. G. Duffy
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Renin Activity ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Contralateral Kidney ◽  
The One ◽  
Renin Content

1. Blood pressure, the hypotensive effect of captopril, plasma renin activity, renal renin content and kidney weight were measured in the two-kidney—one-clip model, the one-kidney—one-clip model and the two-kidney—one-clip model with the ureter of the contralateral kidney ligated in rats. The ureteric ligation was performed to abolish urinary excretion from the contralateral kidney in the two-kidney—one-clip model. 2. The development of hypertension after renal artery constriction was earlier and greater in the one-kidney—one-clip model and the two-kidney—one-clip model with ureter of the contralateral kidney ligated than in the two-kidney—one-clip model. A single oral dose of captopril produced a greater fall in blood pressure in both the two-kidney models than in the one-kidney—one-clip group. 3. Plasma renin activity and renal renin content of the clipped kidney were higher in the two-kidney model rats, whether or not the ureter had been ligated, than in the one-kidney—one-clip model animals, although more than half the rats from the two-kidney model had normal values. There was a significant correlation between plasma renin activity and the response to captopril in all groups, whereas in none of the three groups was the correlation between plasma renin activity and blood pressure significant. 4. The clipped kidney had a higher renin content than did the contralateral kidney, and the weight of the ischaemic kidney was decreased compared with the contralateral kidney whether it was untouched or had its ureter ligated. The weight of the clipped kidney was in the order one-kidney—one-clip model > two-kidney—one-clip model with ureter of the contralateral kidney ligated > two-kidney—one-clip model. 5. It was concluded that the renin-angiotensin system was stimulated to the similar degree in some animals for the two-kidney—one-clip models, whether or not the ureter of the contralateral kidney had been ligated, compared with the one-kidney—one-clip animals. This finding suggests that the contralateral kidney can stimulate renin secretion and synthesis in the clipped kidney independently of Na+ excretion.

Urinary Prostaglandin E2 and Kallikrein Excretion in Glucocrticoid Hypertension in Rats

1983 ◽  
Vol 65 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Michiko Handa ◽  
Kazuoki Kondo ◽  
Hiromichi Suzuki ◽  
Takao Saruta
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Prostaglandin E2 ◽  
Urine Volume ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Plasma Aldosterone ◽  
Renin Activity ◽  
Concurrent Administration ◽  
Angiotensin System

1. Oral administration of dexamethasone (about 2.5 × 10-7 mol/day) caused hypertension in rats. The blood pressure rose from 108 ± 6 (mean ± sd) to 156 ± 17 mmHg on the seventh day. The urine volume and urinary excretion of sodium were increased. The plasma renin activity and plasma aldosterone were unchanged. However, the urinary excretions of prostaglandin E2 (UPGE2V) and kallikrein (Ukall.V) were markedly decreased throughout the experiment. 2. With concurrent administration of captopril, the elevation of blood pressure was partially prevented. in this group of rats, the plasma renin activity was elevated and the reductions in UPGE2V and Ukall.V were partially prevented. 3. Based on these results, it is suggested that suppression of the kallikrein—kinin and prostaglandin systems, in addition to involvement of the renin-angiotensin system, is one of the factors contributing to the hypertensive action of dexamethasone.

DOSE-DEPENDENT BIFURCATION ANALYSIS OF PLASMA RENIN ACTIVITY AFTER NICARDIPINE TREATMENT

2019 ◽  
pp. 84-88
Author(s):  
Kaloyan Yankov
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Bifurcation Analysis ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Renin Activity ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
The Stability ◽  
The Impact

Renin-angiotensin system is one of the general regulatory mechanisms of blood pressure. The activity of the system depends on the rate of renin secretion, therefore, plasma renin activity (PRA) is one of the main variables that mediates the effect of a number of factors on blood pressure. Consequently, the impact of a particular drug on blood pressure disorders can be evaluated by the PRA changes. In clinical practice, the administered therapeutic dose is of critical nature, and a number of methods are known for its calculation. In the present study, applying bifurcation analysis the range of the administered doses of the nicardipine (antihypertensive drug) are determined. The bifurcation diagrams show how the stability of the renin-angiotensin system depends on the administered dose.

Role of the Brain Iso-Renin-Angiotensin System in Experimental Hypertension in Rats

1981 ◽  
Vol 61 (2) ◽  
pp. 175-180 ◽  
Author(s):  
Hiromichi Suzuki ◽  
Kazuoki Kondo ◽  
Michiko Handa ◽  
Takao Saruta
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Renin Activity ◽  
Cerebral Ventricles ◽  
Hypertensive Rats ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
The Brain

1. To examine the possible participation of the brain iso-renin-angiotensin system in the control of blood pressure, as well as in the regulation of plasma renin activity, saralasin and captopril were injected into the cerebral ventricles of three types of experimental hypertensive rats with different plasma renin profiles. 2. Injection of saralasin and captopril into the cerebral ventricles resulted in a significant decrease in blood pressure of two-kidney, one-clip Goldblatt hypertensive rats (11 ± 2 and 9 ± 3 mmHg respectively) and that of spontaneously hypertensive rats (13 ± 2 and 12 ± 2 mmHg respectively), but in deoxycorticosterone (DOC)-salt hypertensive rats injection of these two agents showed a significant increase in blood pressure (13 ± 2 and 12 ± 3 mmHg respectively). 3. The plasma renin activity was markedly decreased after injection of saralasin and captopril into the cerebral ventricles of two-kidney, one-clip Goldblatt hypertensive rats. Conversely, in DOC-salt hypertensive rats, the plasma renin activity was markedly increased after injection of these two agents. In spontaneously hypertensive rats these agents caused no significant change in plasma renin activity. 4. These findings suggest that the brain iso-renin-angiotensin system participates in the central regulation of blood pressure and may be responsible for modulation of the peripheral renin-angiotensin system.

Changes in Plasma Renin Activity and Blood Pressure after Acute and Chronic Administration of β-Adrenergic Receptor-Blocking Drugs

1974 ◽  
Vol 48 (s2) ◽  
pp. 81s-83s
Author(s):  
T. Morgan ◽  
S. Carney ◽  
R. Roberts
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Renin Angiotensin System ◽  
Chronic Administration ◽  
Plasma Renin ◽  
Renin Activity ◽  
Hypotensive Action ◽  
Angiotensin System ◽  
Basal Plasma ◽  
Adrenergic Blocking

1. Prindolol and propranolol chronically cause a fall in mean blood pressure and mean plasma renin activity, but no correlation was observed between the two variables. 2. The response of blood pressure to prindolol and propranolol was not predicted by the basal plasma renin activity. 3. Propranolol administered acutely caused the plasma renin activity to fall with no acute change in blood pressure, whereas prindolol caused the blood pressure to fall with no change in plasma renin activity. 4. The effects of β-adrenergic-blocking drugs on plasma renin activity and blood pressure can be dissociated and it is unlikely that their hypotensive action is mediated through the renin-angiotensin system. 5. Basal plasma renin activity does not identify the patients who will respond to β-adrenergic-blocking drugs.

scholarly journals DOSE-DEPENDENT BIFURCATION ANALYSIS OF PLASMA RENIN ACTIVITY AFTER NICARDIPINE TREATMENT

2019 ◽  
Vol 7 (3) ◽  
pp. 179-183
Author(s):  
Kaloyan Yankov
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Bifurcation Analysis ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Renin Activity ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
The Stability ◽  
The Impact

Renin-angiotensin system is one of the general regulatory mechanisms of blood pressure. The activity of the system depends on the rate of renin secretion, therefore, plasma renin activity (PRA) is one of the main variables that mediates the effect of a number of factors on blood pressure. Consequently, the impact of a particular drug on blood pressure disorders can be evaluated by the PRA changes. In clinical practice, the administered therapeutic dose is of critical nature, and a number of methods are known for its calculation. In the present study, applying bifurcation analysis the range of the administered doses of the nicardipine (antihypertensive drug) are determined. The bifurcation diagrams show how the stability of the renin-angiotensin system depends on the administered dose.

Blood Pressure Response of Nephrectomized Hypertensive Rats to Converting Enzyme Inhibition: Evidence for Persistent Vascular Renin Activity

1977 ◽  
Vol 52 (3) ◽  
pp. 299-304 ◽  
Author(s):  
H. Thurston ◽  
J. D. Swales
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Enzyme Inhibitor ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Renin Activity ◽  
Converting Enzyme ◽  
Bilateral Nephrectomy ◽  
Hypertensive Rats ◽  
Angiotensin System

1. Blood pressure and plasma renin activity were studied after bilateral nephrectomy in groups of rats with hypertension caused by unilateral renal ischaemia with the opposite kidney left intact. 2. Although blood pressure showed only a small fall in the first hour after bilateral nephrectomy, plasma renin activity fell rapidly with a half-life of 10 min. 3. Infusion of converting enzyme inhibitor (SQ20881) produced a 26·1% fall in blood pressure 1 h after nephrectomy, 24·0% at 2 h and 4·6% at 6 h. 4. An angiotensin antagonist (Sar1-Ala8-angiotensin II) was infused into hypertensive rats 1 h after nephrectomy; this blocked the vasodepressor action of the converting enzyme inhibitor, indicating that the fall in blood pressure produced by the inhibitor was due to its action upon the renin-angiotensin system. 5. The renin—angiotensin system maintains blood pressure in this model even after plasma renin has fallen to insignificant levels. This supports the view that vascular renin activity has a longer half-life than circulating renin and is important in the control of blood pressure.

Effect of Neonatal Sympathectomy with 6-Hydroxydopamine on Reactivity of the Renin-Angiotensin System in Spontaneously Hypertensive Rats

1980 ◽  
Vol 59 (2) ◽  
pp. 123-129 ◽  
Author(s):  
A. R. Sinaiko ◽  
M. J. Cooper ◽  
B. L. Mirkin
Keyword(s):  
Plasma Renin Activity ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Renin Activity ◽  
Hypertensive Rats ◽  
Angiotensin System ◽  
Spontaneously Hypertensive ◽  
Renin Angiotensin ◽  
Noradrenaline Concentration ◽  
6 Hydroxydopamine

1. Chemical sympathectomy was produced in spontaneously hypertensive rats by intraperitoneal injection of 6-hydroxydopamine hydrobromide (6-OHD) (100 μg/g body weight) on days 1, 4 and 7 of neonatal life and weekly thereafter until 6 weeks of age. The dose was then reduced to 50 μg/g body weight and injected every 2 weeks. 2. Studies were performed at 6 and 12 weeks of age in pentobarbital-anaesthetized rats. Plasma renin activity was measured before and 5 and 15 min after the administration of intravenous hydrallazine (5 mg/kg). Tissue noradrenaline concentration was determined in brains, hearts and kidneys from rats killed immediately upon completion of blood sampling. 3. The blood pressure of 6-OHD-treated rats was significantly lower than in untreated rats at 6 weeks (117 ± 3 and 146 ± 2 mmHg respectively) and 12 weeks (151 ± 5 and 196 ± 4 mmHg respectively). 4. Kidneys and hearts from 6-OHD-treated rats demonstrated a highly significant reduction in noradrenaline concentration at both 6 and 12 weeks; brain noradrenaline in treated rats was normal at 6 weeks and reduced only to 80% of normal at 12 weeks. 5. Control (pre-hydrallazine) plasma renin activity was significantly lower in 6-OHD-treated rats at 6 and 12 weeks. Nevertheless, renin release in response to intravenous hydrallazine, expressed in terms of absolute values of plasma renin activity, was not significantly different in the treated and untreated rats. When the percentage increase in plasma renin activity from control to 15 min post-hydrallazine samples was calculated, the response of the 6-OHD-treated rats was found to be significantly greater than the response in the untreated rats at each age. 6. These data show that treatment of neonatal rats with 6-OHD results in a significant reduction in basal activity of the renin-angiotensin system but does not interfere with the release of renin in response to hypotensive stress. In cases of severe compromise of adrenergic nervous system function, alternative mechanisms exist which allow the renin-angiotensin system to manifest a maximal response in order to maintain cardiovascular homeostasis.

Effects of Acupuncture on Blood Pressure and Plasma Renin Activity in Two-Kidney One Clip Goldblatt Hypertensive Rats

1994 ◽  
Vol 22 (03n04) ◽  
pp. 215-219 ◽  
Author(s):  
Ho Sub Lee ◽  
Jung Yoo Kim
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Hemodynamic Effect ◽  
Renin Activity ◽  
Hypertensive Rats ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
And Control

Shih-Hsüan [Sipseon(EX-UE-11)] are Curious loci lying outside of the meridians on the tips of each finger. These loci have long been the acupuncture sites for the treatment of cardiovascular disease in oriental medicine. Alterations in the renin-angiotensin system have been considered as the pathophysiological basis of the origin and/or maintenance of hypertension. Activation of the plasma or tissue renin-angiotensin system may be one of the cause of hypertension. The aim of the present study was to elucidate the effects of acupuncture on blood pressure and plasma renin activity. Acupuncture was applied on the EX-UE-11 of two-kidney one clip Goldblatt hypertensive rats. Both the systolic blood pressure and the plasma renin activity decreased significantly after treatment with acupuncture on the EX-UE-11. In the sham-operated and control rats, the procedure influenced the parameters without significant changes. The results suggest that the suppressive hemodynamic effect of acupuncture on the EX-UE-11 may be related to changes in plasma renin activity.

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