Various facets of activation of inactive renin by acidification or cold exposure were investigated in normal human plasma. The acid activation obtained by titration was usually less than that by dialysis method, but varied from 41% to 122% of the latter. The acid phase of acid activation accounted for about 70% of the total activation achieved by the combined effects of the acid and alkaline ph...

Although it has been known for many years that the renin-angiotensin system is responsive to decreases in renal perfusion pressure (1-3), it was only recently discovered that angiotensin is an important regulator of aldosterone secretion (4-6). Before it was known that angiotensin had a role in the regulation of aldosterone secretion, a large number of studies indicated that experimental or pat...

Three siblings (1 boy, 2 girls) with hypertension and hypokalemia are presented, two with low plasma aldosterone and suppressed renin activity and the eldest with a high renin and aldosterone level due to secondary changes in her kidneys. Urinary tetrahydrocortisol (THF) was increased relative to tetrahydrocortisone (THE). Cortisol ring A reduction constant was also lower than normal. Thes...

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.) x 10(-3)/ml to 430 (range 300-500) G.U. x ...

The purpose of this study was to investigate the biochemistry and the regulation of the brain renin-angiotensin system in the Sprague-Dawley rat. Renin activity and angiotensinogen concentrations (direct and indirect radioimmunoassays) were measured in several brain areas and in neuroendocrine glands. Regional renin activities were measured in separate groups of rats on high and low NaCl diets....

Prorenin is secreted by mammalian cells transfected with a human preprorenin expression construct. The purpose of this investigation was to compare the physicochemical properties of expressed prorenin in culture medium with the known characteristics of human inactive renin, which accounts for nearly half the renin in plasma and kidney. We found that expressed human prorenin strongly resembles h...

Renin is a circulating proteolytic enzyme acting at the physiological pH of blood; a circulating inhibitor of this enzyme has not been identified. Therefore, most studies on the biological significance of renin are based on the classical model of a circulating hormone. Renin, however; does not act on cellular receptors; it acts by virtue of its enzymatic activity. Evidence has accumulated in re...

Human plasma and amniotic liquid were activated by dialysis at pH 3.3. Then, renin before and after acidification was determined by two methods: enzymatic activity measurement, and direct radioimmunoassay. The identity between nonactivated and activated renin in plasma and amniotic fluid on the one hand, and pure renin on the other, was demonstrated by the dilution curves in radioimmunoassay. A...

Plasma renin activity is suppressed in approximately 25% of patients with essential hypertension, and the rate of in vitro angiotensin I production after addition of exogenous renin (renin reactivity) is increased in plasma of hypertensive patients. We have recently observed that blood pressure (116 +/- 1.5/68 +/- 1.7 mm Hg) of young women who had hypertension during a first pregnancy 3--6 year...

Renin activity is separated from rabbit plasma by globulin precipitation, dialysis, and DEAE cellulose column chromatography with a Tris chloride buffer system and acid elution, followed by ultrafiltration. The plasma renin extract contains no renin substrate and no angiotensinase activity can be detected after incubation with angiotensin for 200 hr. Incubation with a known concentration of rab...