Characterization of Aggression-Provoked Renin from An Unknown Source in Male Mice

1981 ◽  
Vol 61 (4) ◽  
pp. 373-378 ◽  
Author(s):  
K. Poulsen ◽  
E. B. Pedersen
Keyword(s):  
Enzymatic Activity ◽  
Control Level ◽  
Plasma Renin ◽  
Fold Increase ◽  
Male Mice ◽  
Angiotensin I ◽  
Renin Substrate ◽  
Specific Enzymatic Activity ◽  
Aspartate Proteinase

1. In male mice without kidneys and submaxillary, as well as sublingual, glands aggressive behaviour causes a vast release of renin [J. Bing & K. Poulsen (1979) Acta Physiologica Scandinavica, 107, 251–256]. 2. This resulted in about an 800-fold increase in plasma renin concentration from the control level of 0.52 (range 0.15-0.8) Goldblatt unit (G.U.) × 10−3/ml to 430 (range 300–500) G.U. × 10−3/ml after aggression. 3. The aggression-provoked renin fulfil all the criteria so far studied for being active renin, identical with normal mouse plasma renin and pure submaxillary mouse renin. 4. It generates angiotensin I with renin substrate and Km (1.2 μmol/l) is the same. It is neutralized by pepstatin but not by inhibitors of metallo-, thiol and serine proteinases, indicating that it is an aspartate proteinase (acidic proteinase). 5. It is a 40 000-mol.wt. renin, which has full enzymatic activity with a specific enzymatic activity of 0.32 G.U./μg, identical with that of normal plasma renin. 6. Its enzymatic activity is neutralized by a specific antibody against pure submaxillary renin. It is measurable in the direct renin radioimmunoassay with a dilution curve which parallels that of the standards. It demonstrates complete antigenic identity with pure submaxillary renin in crossed immunoelectrophoresis. 7. Its origin is unknown.

Aggression-Provoked Renin Release from An Unknown Source in Male Mice

1981 ◽  
Vol 61 (s7) ◽  
pp. 257s-259s ◽  
Author(s):  
K. Poulsen ◽  
E. B. Pedersen
Keyword(s):  
De Novo ◽  
Plasma Renin ◽  
Fold Increase ◽  
Acid Proteinase ◽  
Male Mice ◽  
Angiotensin I ◽  
Submaxillary Glands ◽  
Specific Enzymatic Activity ◽  
Inactive Renin

1. An 800-fold increase in plasma renin occurs after aggressive behaviour in male mice without kidneys and submaxillary glands. 2. The aggression-provoked renin fulfils all the criteria so far studied for being identical with renin. 3. It is an acid proteinase which generates angiotensin I with the same Km and specific enzymatic activity as pure submaxillary renin and normal plasma renin. 4. It is immunologically identical with submaxillary renin in the direct renin assay and in crossed immunoelectrophoresis. 5. It is present in plasma as fully enzymatically active 40 000-mol. wt. renin. 6. It is not likely that it arises from an inactive precursor or binding protein in plasma, since there is no inactive renin present and the high-molecular-weight forms of renin are also present after the fighting. 7. None of many organs so far studied can account for the release. 8. Synthesis of renin de novo during fighting is not likely since it is released also after blockade in vivo of protein synthesis. 9. Origin of the renin is unknown.

Enzymatic Activity of Renin in Plasma of Normal and Uraemic Subjects

1984 ◽  
Vol 67 (3) ◽  
pp. 365-368 ◽  
Author(s):  
Theodore A. Kotchen ◽  
Tam T. Guyenne ◽  
Pierre Corvol ◽  
Joel Menard
Keyword(s):  
Renal Failure ◽  
Enzymatic Activity ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Renin Activity ◽  
Angiotensin I ◽  
Renin Substrate ◽  
Inactive Renin ◽  
Substrate Concentrations

1. Plasma renin reactivity (PRR) is the rate of angiotensin I production after addition of renin to plasma, minus endogenous renin activity. PRR is increased in plasma of patients with renal failure compared with that of normal subjects. The present study was carried out to determine if increased PRR in uraemic plasma is related to differences of endogenous active or inactive renin, endogenous renin substrate, or pH of the incubation in vitro. 2. PRR in plasma of ten uraemic patients was greater (P<0.02) than that in plasma of ten normal subjects in incubations carried out at pH 7.4 and 5.7. 3. Increased PRR was not accounted for by differences of endogenous active and inactive renin activity. 4. After addition of renin, renin concentration (measured by direct radioimmunoassay) did not differ in normal and uraemic plasma. 5. Renin substrate concentration, measured both indirectly and by direct radioimmunoassay, also did not differ in normal and uraemic plasma. 6. Increased PRR in uraemic plasma is not related to alterations of renin or renin substrate concentrations. These observations are consistent with our earlier hypothesis that there is a deficiency of a renin inhibitor in uraemic plasma.

Reninlike enzymatic activity in the cerebral microvessels of the rat

1980 ◽  
Vol 238 (3) ◽  
pp. H384-H388 ◽  
Author(s):  
H. Kowaloff ◽  
H. Gavras ◽  
P. Brecher
Keyword(s):  
Enzymatic Activity ◽  
Specific Activity ◽  
Plasma Renin ◽  
Fold Increase ◽  
Maximal Activity ◽  
Renin Activity ◽  
Renin Substrate ◽  
Cerebral Microvessels ◽  
Measurable Activity ◽  
Extrarenal Renin

Extrarenal renin has been a subject of considerable interest. Chiefly, studies have focused on brain and vascular renin activity in large arteries. A method now exists for the isolation from the cerebrum of microvascular tissues consisting of arterioles, capillaries and venules. The present study has demonstrated reninlike enzymatic activity within the cerebral microvasculature of the rat that is distinct from plasma renin activity. Maximal activity was observed at pH 4.5 with no measurable activity at pH 7.4. Activity with homologous renin substrate was only 13% of that measured with hog substrate whereas a 400-fold increase in reninlike specific activity was observed when microvessel homogenates were incubated with synthetic tetradecapeptide renin substrate. Bilateral nephrectomy did not affect microvascular reninlike activity. Pepstatin 15 nM, abolished reninlike activity in microvessel homogenates. Mean specific microvessel reninlike activity was 1.15 +/- 0.20 pg angiotensin I . microgram protein-1 . h-1 in control animals. Neither sodium depletion nor DOC-saline administrations caused a significant change in microvascular reninlike activity. It is suggested that the reninlike activity observed in microvessels is an acid protease, perhaps cathepsin D derived from lysosomes.

Measurement of inactive renin in normal, nephrectomized, and adrenalectomized rats

1991 ◽  
Vol 69 (9) ◽  
pp. 1381-1384 ◽  
Author(s):  
Knud Poulsen ◽  
Arne Høj Nielsen ◽  
Arne Johannessen
Keyword(s):  
Animal Model ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Plasma Renin ◽  
Rat Plasma ◽  
Angiotensin I ◽  
Renin Substrate ◽  
Suitable Animal Model ◽  
Inactive Renin ◽  
Adrenalectomized Rats

In a new method for measurement of inactive rat plasma renin, the trypsin generated angiotensin I immunoreactive material, which was HPLC characterized as similar to tetradecapeptide renin substrate, is removed by a cation exchange resin before the renin incubation step. The method also corrects for trypsin destruction of endogenous angiotensinogen by the addition of exogenous angiotensinogen. When measured with this method inactive renin in rat plasma decreased after nephrectomy and increased after adrenalectomy. This is in accordance with findings in humans. A sexual dimorphism of prorenin (inactive renin) in rat plasma, similar to that reported in humans and mice, was demonstrated. Thus, inactive renin in the rat is no exception among species, and the rat might be a suitable animal model for further studies dealing with the physiology of prorenin in plasma and tissues.Key words: angiotensinogen, inactive renin, renin.

ESTIMATION OF MARSUPIAL RENIN USING MARSUPIAL RENIN-SUBSTRATE

1972 ◽  
Vol 53 (1) ◽  
pp. 125-130 ◽  
Author(s):  
PAMELA A. SIMPSON ◽  
J. R. BLAIR-WEST
Keyword(s):  
Substrate Concentration ◽  
Structural Difference ◽  
Plasma Renin ◽  
Angiotensin I ◽  
Ph Optimum ◽  
Ph Profile ◽  
Renin Substrate ◽  
Grey Kangaroo ◽  
Rate Of Reaction ◽  
Highly Correlated

SUMMARY Bilateral nephrectomy of an Eastern Grey kangaroo (Macropus giganteus) increased plasma renin-substrate concentration approximately tenfold when compared with intact kangaroos. A preparation made from this plasma had a renin-substrate concentration of 3000 ng/ml. A pH profile of rate of reaction with pig renin had an optimum at pH 5·39. By comparison, the pH optimum of sheep renin-substrate was pH 6·15. Estimates of plasma renin concentration for kangaroos, wombats and wallabies, using kangaroo renin-substrate or sheep renin-substrate were highly correlated. Results from incubation with sheep renin-substrate were greater and hence indicate the advantage in using this substrate for marsupial renin estimation. The consistently large difference between sheep and kangaroo renin-substrate when incubated with renin from marsupial and eutherian species appears to be due to a structural difference between the two substrates, probably near the C-terminal end of the angiotensin I molecule.

Methods for serial study of renin-angiotensin system in the unanesthetized rat

1975 ◽  
Vol 228 (2) ◽  
pp. 369-375 ◽  
Author(s):  
JS Carvalho ◽  
R Shapiro ◽  
P Hopper ◽  
LB Page
Keyword(s):  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Rat Plasma ◽  
Angiotensin I ◽  
Ether Anesthesia ◽  
Renin Substrate ◽  
Angiotensin System ◽  
Arterial Blood ◽  
Sympathetic Nervous ◽  
Improved Technique

Micromethods for measurement of plasma renin concentration (PRC) and plasma renin-substrate concentration (PSC) have been developed for rat plasma with radioimmunoassay of angiotensin I. An improved technique for aortic implantation of plastic cannulas was developed for use in experiments 1-2 wk in duration. The effects on components of renin system of anesthesia and tail cutting were studied. Arterial blood was sampled through cannulas without animal manipulation. PRC varied little in unanesthetized rats, was moderately and variably increased during pentobarbital anesthesia, and was markedly and consistently elevated during ether anesthesia. PSC was unchanged during anesthesia. PRC was increased in blood obtained by tail cutting within 1-2 min after cutting. With the use of the methods and techniques described here serial studies of the renin system in plasma of unanesthetized rats are shown to be feasible. A role for the sympathetic nervous system in the mediation of renin secretion by ether is proposed.

Plasma Renin Activity and Plasma Renin Substrate in Hypertension Associated with Steroid Excess

1973 ◽  
Vol 45 (s1) ◽  
pp. 295s-299s ◽  
Author(s):  
L. R. Krakoff ◽  
M. Mendlowitz
Keyword(s):  
Oral Contraceptive ◽  
Plasma Renin Activity ◽  
Cushing’S Syndrome ◽  
Plasma Renin ◽  
Cushing's Syndrome ◽  
Glucocorticoid Therapy ◽  
Renin Activity ◽  
Angiotensin I ◽  
Renin Substrate ◽  
Contraceptive Agents

1. Plasma renin activity and plasma renin substrate were measured by radioimmunoassay of generated angiotensin I in patients with steroid excess syndromes. Significant increases in substrate were observed in patients with Cushing's syndrome, during glucocorticoid therapy and on oral contraceptive agents. Suppression of plasma renin activity occurred only in primary aldosteronism. 2. The Michaelis constant (Km) for the reaction between renin and substrate in plasma at physiological pH (7.4) was also determined. The extent to which elevated plasma renin substrate increases the velocity of angiotensin I formation was then calculated. 3. In patients with Cushing's syndrome, glucocorticoid therapy or oral contraceptive use, elevated renin substrate coupled with failure of suppression of circulating renin results in increased angiotensin I formation.

MEASUREMENT OF PLASMA RENIN-SUBSTRATE IN MAN

1973 ◽  
Vol 56 (2) ◽  
pp. 159A-171 ◽  
Author(s):  
MALCOLM TREE
Keyword(s):  
Angiotensin Ii ◽  
Substrate Concentration ◽  
Plasma Renin ◽  
Angiotensin I ◽  
Renin Substrate ◽  
Potential Sources ◽  
Sources Of Variation ◽  
Method Of Measurement ◽  
Inhibitor Solution

SUMMARY Values of plasma renin-substrate concentration in man vary widely according to the method of measurement used. Potential sources of variation have been tested and, as far as possible, excluded in the method described here. Blood was diluted rapidly in an angiotensinase-inhibitor solution containing EDTA and phenanthroline; plasma was separated by centrifugation and the renin-substrate in the specimen was hydrolysed by renin to angiotensin I which was identified as such by chromatography and radioimmunoassay. Angiotensin I was used as a standard to determine the amount of angiotensin formed on incubation. Use of angiotensin II for a standard, as in other methods, led to falsely low values of plasma renin-substrate concentration. Recovery of added substrate was 94%. Changes of plasma renin-substrate concentration in some physiological and pathological states are reported briefly.

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