Inactive Renin in Rabbit Plasma: Effect of Haemorrhage

1979 ◽  
Vol 56 (2) ◽  
pp. 105-108 ◽  
Author(s):  
H. K. Richards ◽  
S. A. Grace ◽  
A. R. Noble ◽  
K. A. Munday
Keyword(s):  
Blood Vessels ◽  
Renin Activity ◽  
Bilateral Nephrectomy ◽  
Rabbit Plasma ◽  
Inactive Form ◽  
Inactive Renin ◽  
Plasma Effect

1. Renin activity in rabbit plasma increases after acidification (pH 3·3), probably due to activation of an inactive form of renin. 2. Both active and inactive renin in plasma increase after haemorrhage. This stimulus does not change the relative proportions of the two forms. 3. After ligation of the renal blood vessels neither form of renin increases in response to haemorrhage. 4. One day after bilateral nephrectomy no inactive renin could be demonstrated in plasma. 5. In the rabbit, therefore, the kidney is a major source of the inactive renin in plasma.

Inactive Renin in Rabbit Plasma: Effect of Frusemide

1981 ◽  
Vol 60 (4) ◽  
pp. 393-398 ◽  
Author(s):  
H. K. Richards ◽  
D. J. Lush ◽  
A. R. Noble ◽  
K. A. Munday
Keyword(s):  
Plasma Levels ◽  
Time Course ◽  
Rabbit Plasma ◽  
Active Renin ◽  
Inactive Form ◽  
Plasma Active Renin ◽  
Inactive Renin ◽  
Time Courses ◽  
Induced Changes ◽  
Sodium And Potassium

1. An inactive form of renin exists in rabbit plasma. This can be activated, and therefore measured, after acidification (pH 2.8). 2. The effect of frusemide diuresis, with replacement of volume losses, on plasma levels of active and inactive renin was studied over a 3 1/2 h time course. Plasma active renin increased during frusemide diuresis but inactive renin disappeared from the circulation. The time courses for the changes in the two forms of renin were similar. 3. The peak of the frusemide-induced changes in renal function (urine flow, sodium and potassium excretion and creatinine clearance) preceded the maximum changes in the two forms of renin by 90 min. 4. The response of plasma levels of inactive renin to physiological stimuli depends on the nature of the stimulus, as well as its duration. Some form of sodium-sensitive mechanism may control the activation of inactive renin.

Trypsin-Activatable Inactive Renin in Rat Plasma

1983 ◽  
Vol 64 (2) ◽  
pp. 137-140 ◽  
Author(s):  
Nicola Glorioso ◽  
Paolo Madeddu ◽  
Paolo Dessi'-Fulgheri ◽  
Giuseppe Fois ◽  
Franca Meloni ◽  
...  
Keyword(s):  
Rat Plasma ◽  
Renin Activity ◽  
Trypsin Activity ◽  
Ph Optimum ◽  
Renin Substrate ◽  
Inactive Form ◽  
Wide Range ◽  
Maximal Activation ◽  
Inactive Renin ◽  
Range Of Variation

1. Activation of inactive renin in rat plasma has been studied with different trypsin concentrations and incubation times at pH 6.2 and 4°C. 2. Trypsin concentrations below 2 mg/ml, lower than endogenous rat plasma anti-trypsin activity, do not activate inactive renin, whereas maximal activation is obtained with trypsin at 6 mg/ml for 1 min at 4°C, pH 6.2. 3. Under these conditions trypsin can cleave dialysable fragments from renin substrate. ANG I can be generated at 37°C with a pH optimum of 5.3. Nevertheless, the ANG I formation at pH 6.2 was totally unaffected. 4. Incubations longer than 2 min with trypsin at 6 mg/ml can induce a direct cleavage of dialysable ANG I-containing fragments strongly interfering with the measurements of renin activity at pH 6.2. 5. On average 40% of the total renin measured in plasma of normotensive WK rats is in the inactive form, although a wide range of variation is observed.

L-arginine analogues inhibit aldosterone secretion in rats

1995 ◽  
Vol 268 (5) ◽  
pp. R1137-R1142 ◽  
Author(s):  
J. C. Simmons ◽  
R. H. Freeman
Keyword(s):  
Blood Flow ◽  
Angiotensin Ii ◽  
Methyl Ester ◽  
Arterial Pressure ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Renin Activity ◽  
Bilateral Nephrectomy ◽  
Aldosterone Secretion ◽  
Series Of Experiments

L-Arginine analogues, e.g., NG-nitro-L-arginine methyl ester (L-NAME), increase arterial pressure and suppress renin release in the rat. On the basis of these observations, it was hypothesized that L-arginine analogues also would attenuate aldosterone secretion. This hypothesis was tested in anesthetized rats treated with L-NAME or NG-nitro-L-arginine (L-NNA, 185 mumol/kg ip). The aldosterone secretion rate, plasma renin activity, and adrenal blood flow were attenuated in rats treated with L-NAME and L-NNA compared with control animals. Similar experiments were performed in anephric rats to examine the effects of L-NAME on aldosterone secretion independent of the circulating reninangiotensin system. The administration of L-NAME reduced adrenal blood flow but failed to reduce aldosterone secretion in these anephric rats. Bilateral nephrectomy reduced plasma renin activity essentially to undetectable levels in these animals. In a third series of experiments, two groups of anephric rats were infused with angiotensin II (3 micrograms/kg body wt iv) to provide a stimulus for aldosterone secretion. Aldosterone secretion and adrenal blood flow were markedly reduced in angiotensin II-infused rats pretreated with L-NAME compared with the control anephric animals infused with angiotensin II. Overall these results suggest that L-arginine analogues attenuate aldosterone secretion by inhibiting the adrenal steroidogenic effects of endogenous or exogenous angiotensin II and/or by reducing plasma levels of renin/angiotensin.

Does heparin inhibit renin activity?

1991 ◽  
Vol 69 (9) ◽  
pp. 1360-1363 ◽  
Author(s):  
Masato Matsunaga ◽  
Yoko Yamanaka ◽  
Noriko Nagano ◽  
Yuki Iwasaki ◽  
Yumi Saito ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Vascular Smooth Muscle Cell ◽  
Plasma Renin ◽  
Renin Activity ◽  
Renin Substrate ◽  
Significant Difference ◽  
Inactive Renin

Although heparin was reported in the 1960s to inhibit renin activity, this has not always been confirmed by other investigators. Hence, we re-examined whether heparin really inhibits renin or not. Renin activities were determined by radioimmunoassay of angiotensin I generated at pH 7.4. (i) No significant difference was found between the two kinds of plasma samples obtained with heparin and with EDTA as anticoagulant, in ARC (renin activity with addition of sheep renin substrate), TRC (ARC after activation of inactive renin by trypsin), or PRA (plasma renin activity without additional substrate), (ii) Even in higher concentrations of heparin up to 500 U/mL, neither PRA, ARC, nor TRC of plasma was affected significantly. (iii) Heparin, in concentrations up to 500 U/mL, exerted no significant effect on TRC of the media of human vascular smooth muscle cell culture. In conclusion, heparin does not exert any significant inhibitory effect on human renin nor does it affect activation of inactive renin by trypsin in the range of concentration of practical use, under the conditions employed in this study.Key words: plasma renin, tissue renin, inactive renin, vascular smooth muscle cell, trypsin.

Effects of Bilateral Nephrectomy on Blood Pressure and Renin Activity

1972 ◽  
Vol 107 (5) ◽  
pp. 677-679
Author(s):  
J.W. Mostert ◽  
R.H. Moore ◽  
G.P. Murphy
Keyword(s):  
Blood Pressure ◽  
Renin Activity ◽  
Bilateral Nephrectomy

Absence of Activation in Vitro of Renin in Rat Plasma

1982 ◽  
Vol 62 (4) ◽  
pp. 435-437 ◽  
Author(s):  
M. H. De Keijzer ◽  
A. P. Provoost ◽  
F. H. M. Derkx
Keyword(s):  
Human Plasma ◽  
Active Form ◽  
Plasma Renin ◽  
Rat Plasma ◽  
Plasma Renin Concentration ◽  
Inactive Form ◽  
Inactive Renin

1. Rat plasma was subjected at 4°C to various treatments known to convert inactive renin into its active form in human plasma. 2. No statistical differences in plasma renin concentration were found when the levels after the various treatments were compared with that of untreated rat plasma. 3. It is concluded that, in contrast to human plasma, no inactive form of renin is present in rat plasma.

Effect of Acid, Trypsin and Cold Treatment and of Renin— Plasma Interaction on the Activity of Renin Secreted by Rat Kidney

1979 ◽  
Vol 57 (3) ◽  
pp. 233-240 ◽  
Author(s):  
H. Nakane ◽  
Y. Nakane ◽  
P. Corvol ◽  
J. Menard
Keyword(s):  
Rat Kidney ◽  
Cold Treatment ◽  
Rat Plasma ◽  
Renin Activity ◽  
Trypsin Treatment ◽  
Plasma Interaction ◽  
Isolated Perfused Rat Kidney ◽  
Perfused Rat Kidney ◽  
Inactive Renin ◽  
The Difference

1. Renin release from the isolated perfused rat kidney was markedly stimulated by isoprenaline or anoxia. Renin secreted into the blood-free perfusate was not activated by exposure to cold or dialysis to pH 3·3, suggesting the absence either of cryo- or acid-activatable renin or of factors necessary to activate inactive renin. 2. Trypsin treatment did not change renin concentration in the perfusate samples. 3. When binephrectomized rat plasma was added to perfusate samples before dialysis, renin concentration in the acidified samples was significantly higher than in samples dialysed to pH 6·5. Diminished renin recovery in the latter samples caused this difference. Binephrectomized rat plasma itself had no significant renin activity before or after acid dialysis, indicating the absence of any important extrarenal source of active or acid-activatable renin in rats. 4. Acidification of binephrectomized rat plasma before its addition to the perfusate samples markedly reduced the difference between renin recovery during dialysis to pH 3·3 and dialysis to pH 6·5, indicating that acidification irreversibly inhibited renin inactivation by binephrectomized rat plasma. No net increase in renin concentration was observed in any of our experiments. 5. These results suggest that rat kidney does not secrete inactive renin. They also point to the existence of renin inactivation by rat plasma at neutral pH, which might lead to overestimation of acid-activatable renin in rats.

Active and inactive renin in dog plasma before and after bilateral nephrectomy

1981 ◽  
Vol 37 (7) ◽  
pp. 785-786 ◽  
Author(s):  
J. Staessen ◽  
P. Lijnen ◽  
R. Fagard ◽  
A. Amery
Keyword(s):  
Bilateral Nephrectomy ◽  
Dog Plasma ◽  
Before And After ◽  
Inactive Renin

Plasma Renin Activity, Active and Inactive Renin Concentrations, and their Responses to β1-Adrenoceptor Blockade with Metoprolol in Hyperthyroidism

1986 ◽  
Vol 18 (09) ◽  
pp. 630-634 ◽  
Author(s):  
T. Baba ◽  
S. Murabayashi ◽  
K. Aoyagi ◽  
M. Kitaoka ◽  
M. Nakazono ◽  
...  
Keyword(s):  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Renin Activity ◽  
Inactive Renin
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