The amount and biochemical properties of renin excreted by anesthetized dogs were investigated to elucidate the significance of urinary excretion in the metabolism of renin. Mean arterial blood pressure was 127 +/- 4 mm Hg, renal blood flow was 170 +/- 8 ml/min, glomerular filtration rate, 38.6 +/- 2.3 ml/min, and urine flow rate, 0.37 +/- 0.09 ml/min (n = 11). Urinary renin concentration (URC)...

Renin release into plasma has been used to investigate the drug dose-dependence of renin-angiotensin system inhibition because it is proportional to the interruption of the permanent negative feedback loop of angiotensin II on renin secretion. We investigated the 24-hour between-subject differences in renin profiles by analyzing the time-dependence of individual renin responses in 16 mildly sod...

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...

Performance of accurrate, reproducible, and interpretable assays for plasma renin activity and other components of the renin/angiotensin system in the clinical setting requires a clear understanding of the various reactions in the renin/angiotensin cascade and the nature of their interactions. Plasma renin activity, the rate of angiotensin generations from plasma incubated in vitro, is the most...

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...

The renin-angiotensin system is normally subject to servo control mechanisms that suppress plasma renin levels in response to increased blood pressure and increase plasma renin levels when blood pressure falls. In most species, renin is rate limiting, and angiotensinogen circulates at a concentration close to the Km, so varying the concentration of either can affect the rate of angiotensin form...

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...

Renal vein renin activity was measured by bioassay of plasma obtained from anesthetized dogs during renal arterial infusion of sympathomimetic amines, cyclic AMP, and other nucleotides. Renin secretion was calculated as the product of renal blood flow and the arterial-renal venous renin difference. Infusion of cyclic AMP significantly increased renin secretion, while administration of ATP, ADP,...

The primary product of the renin gene is preprorenin. A signal peptide sorts renin to the secretory pathway in juxtaglomerular cells where it is released into the circulation to initiate the renin-angiotensin system cascade. In the brain, transcription of renin occurs from an alternative promoter encoding an mRNA starting with a new first exon (exon 1b). Exon 1b initiating transcripts skip over...

This study aimed to characterize the cellular pathways along which nitric oxide (NO) influences the secretion of renin from the kidney. Using the isolated perfused rat kidney model, we found that the NO donor sodium nitroprusside (SNP) (1-30 μmol/l) induced a prompt, concentration-dependent fourfold increase of basal renin secretion. The membrane-permeable cGMP analogs 8-bromo-cGMP and 8-(4-chl...