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.

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.

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.

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.

Plasma renin activity and forearm blood flow in paraplegic humans

1985 ◽  
Vol 59 (3) ◽  
pp. 924-927 ◽  
Author(s):  
P. R. Freund ◽  
G. L. Brengelmann
Keyword(s):  
Blood Flow ◽  
Plasma Renin Activity ◽  
Forearm Blood Flow ◽  
Control Period ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
The Body ◽  
Renin Activity ◽  
Angiotensin System ◽  
Renin Angiotensin

We recently found that paraplegic humans respond to hyperthermia with subnormal increase in skin blood flow (SkBF), based on measurements of forearm blood flow (FBF). Is this inhibition of SkBF a defect in thermoregulation or a cardiovascular adjustment necessary for blood pressure control? Since high resting plasma renin activity (PRA) is found in unstressed individuals with spinal cord lesions and since PRA increases during hyperthermia in normal humans, we inquired whether the renin-angiotensin system is responsible for the attenuated FBF in hyperthermic resting paraplegics. Five subjects, 28–47 yr, with spinal transections (T1-T10), were heated in water-perfused suits. Blood samples for PRA determinations were collected during a control period and after internal temperature reached approximately 38 degrees C. Some subjects with markedly attenuated FBF had little or no elevation of PRA; those with the best-developed FBF response exhibited the highest PRA. Clearly, circulating angiotensin is not the agent that attenuates SkBF. Rather, increased activity of the renin-angiotensin system may be a favorable adaptation that counters the locally mediated SkBF increase in the lower body and thus allows controlled active vasodilation in the part of the body subject to centrally integrated sympathetic effector outflow.

Dopaminergic Control of Aldosterone Secretion is Independent of the Renin—Angiotensin System in Rats

1980 ◽  
Vol 59 (s6) ◽  
pp. 101s-103s ◽  
Author(s):  
J. R. Sowers ◽  
M. L. Tuck ◽  
J. Barrett ◽  
M. P. Sambhi ◽  
M. S. Golub
Keyword(s):  
Plasma Renin Activity ◽  
Enzyme Inhibitor ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Plasma Aldosterone ◽  
Renin Activity ◽  
Dopamine Antagonist ◽  
Aldosterone Secretion ◽  
Angiotensin System ◽  
Renin Angiotensin

1. In rats, intra-arterial metoclopramide, a dopamine antagonist, resulted in an elevation of plasma aldosterone at 5 min and plasma renin activity at 10 min and peak aldosterone and renin responses at 10 and 30 min respectively. 2. Pre-administration of l-dopa blunted and delayed aldosterone and renin responses to metoclopramide, indicating that metoclopramide-induced plasma aldosterone and plasma renin activity increments are mediated by a direct effect of blockade of dopamine receptors rather than other effects of this drug. 3. Pre-administration of angiotensin converting enzyme inhibitor, captopril (SQ 14 225) and the angiotensin II antagonist, saralasin, as well as bilateral nephrectomy did not significantly affect the aldosterone response to metoclopramide, Thus dopaminergic modulation of aldosterone secretion occurs independently of alterations in the renin-angiotensin system. 4. Modulating effects of dopamine on plasma aldosterone are probably mediated by direct effects as well as by interaction with other factors influencing aldosterone secretion at the adrenal zona glomerulosa.

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.

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