Renin Substrate (Angiotensinogen) as a Possible Erythropoietin Precursor

Author(s):  
F. Fyhrquist ◽  
K. Rosenl�f ◽  
C. Gr�nhagen-Riska ◽  
V. R�s�nen
Keyword(s):  
1991 ◽  
Vol 69 (9) ◽  
pp. 1381-1384 ◽  
Author(s):  
Knud Poulsen ◽  
Arne Høj Nielsen ◽  
Arne Johannessen

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.


1978 ◽  
Vol 56 (9) ◽  
pp. 920-925 ◽  
Author(s):  
N. G. Seidah ◽  
R. Routhier ◽  
M. Caron ◽  
M. Chrétien ◽  
S. Demassieux ◽  
...  

In this paper, we present the amino-terminal sequence of rat tonin, an endopeptidase responsible for the conversion of angiotensinogen, the tetradecapeptide renin substrate, or angiotensin I to angiotensin II. It is shown that isoleucine and proline occupy the amino- and carboxy-terminal residues respectively. The N-terminal sequence analysis permitted the identification of 34 out of the first 40 residue s of the single polypeptide chain composed of 272 amino acids. The se results showed an extensive homology with the sequence of many serine proteases of the trypsin–chymotrypsin family. This information, coupled with the slow inhibition of tonin by diisopropylfluorophosphate, classified this enzyme as a selective endopeptidase of the active serine protease family.


1983 ◽  
Vol 90 (12) ◽  
pp. 1186-1192 ◽  
Author(s):  
ANJA S. I. SIIMES ◽  
ILKKA IMMONEN ◽  
ULF-HAKAN STENMAN ◽  
JORMA E. K. KARKKAINEN ◽  
FREDRIKA PEKONEN ◽  
...  

Science ◽  
1943 ◽  
Vol 98 (2537) ◽  
pp. 153-154
Author(s):  
I. H. Page ◽  
O. M. Helmer ◽  
A. A. Plentl ◽  
K. G. Kohlstaedt ◽  
A. C. Corcoran
Keyword(s):  

1991 ◽  
Vol 69 (9) ◽  
pp. 1360-1363 ◽  
Author(s):  
Masato Matsunaga ◽  
Yoko Yamanaka ◽  
Noriko Nagano ◽  
Yuki Iwasaki ◽  
Yumi Saito ◽  
...  

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.


1988 ◽  
Vol 255 (4) ◽  
pp. F749-F754 ◽  
Author(s):  
H. M. Siragy ◽  
N. E. Lamb ◽  
C. E. Rose ◽  
M. J. Peach ◽  
R. M. Carey

ACRIP is a competitive inhibitor of renin in which an analogue of statine, (3R,4S)-4-amino-3-hydroxy-6-methylheptanoic acid, is incorporated into analogues of porcine renin substrate. ACRIP inhibits the enzymatic activity of renin, thus blocking the initiation of the angiotensin cascade. We studied the intrarenal action of ACRIP in small quantities without measurable systemic effects on renal function. In the first experiment, ACRIP was administered intrarenally at 0.02, 0.2, and 2 micrograms.kg-1.min-1 to uninephrectomized conscious dogs (n = 6) in metabolic balance at sodium intake of 10 meq/day. ACRIP, in doses of 0.02 and 0.2 micrograms.kg-1.min-1, markedly increased urine sodium excretion (UNaV) from 5.8 +/- 1.4 to 15.1 +/- 5.1 and 19.9 +/- 3.2 mu eq/min, respectively. Urinary flow rate (UV) underwent a similar increase and glomerular filtration rate (GFR) increased from 25.7 +/- 2.5 to 35.6 +/- 2.5 at 0.02 micrograms.kg-1.min-1 of ACRIP. Renal plasma flow (RPF), plasma renin activity (PRA), and plasma aldosterone concentration (PAC) were not affected. At 2 micrograms.kg-1.min-1, ACRIP traversed the kidney in quantities large enough to produce a reduction in systemic PRA and mean arterial pressure and caused natriuresis, diuresis, and increased GFR. In a second experiment, ACRIP was administered intrarenally at 0.2 micrograms.kg-1.min-1 in a separate group (n = 4) under identical conditions. ACRIP-induced increases in UV and UNaV were completely blocked by concurrent intrarenal administration of angiotensin II. The results indicate that intrarenal angiotensin II acts as a physiological regulator of renal sodium and fluid homeostasis.


1968 ◽  
Vol 108 (4) ◽  
pp. 679-685 ◽  
Author(s):  
J W Ryan ◽  
J. K. McKenzie ◽  
M. R. Lee

1. EDTA (10mm), 2,3-dimercaptopropan-1-ol (10mm) and chlorhexidine gluconate (0·005%, w/v) cause complete inactivation of plasma enzymes that degrade angiotensin I, but have no effect on the reaction of renin with its substrate. The reagents were termed the selective inhibitors. 2. Thus it is possible to measure renin in plasma by its ability to catalyse the release of angiotensin I. 3. Sterile plasma, treated with the selective inhibitors, is incubated with renin substrate (500–1000ng. of angiotensin content/ml.) at pH6 at 42° for 6hr. 4. Under these conditions the reaction obeys first-order kinetics. Renin activity is calculated in terms of the percentage release of the angiotensin content/hr. 5. As described, the assay is sufficiently sensitive to measure renin in the plasma of all normal rabbits. By extending the length of the incubation, much lower activities can be measured.


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