The renin-angiotensin system (RAS) in the brain is a critical determinant of blood pressure, but the mechanisms regulating RAS activity in the brain remain unclear. Expression of brain renin (renin-b) occurs from an alternative promoter-first exon. The predicted translation product is a nonsecreted enzymatically active renin whose function is unknown. We generated a unique mouse model by select...

The aim of this work was to investigate, in an experimental model of diabetes mellitus, the levels of renin activity in vascular and adrenal tissues and their relationship to several circulating renin-angiotensin system components. Rats with chronic (12 weeks) streptozocin-induced diabetes showed a significant decrease in plasma renin activity (PRA), plasma renin concentration, and plasma aldos...

Hypertension is associated with accelerated bone loss, and the renin-angiotensin-aldosterone system is a key regulator of blood pressure. Although components of this system are expressed in human bone cells, studies in humans are sparse. Thus, we studied the association of circulating renin and aldosterone with osteocalcin and bone mineral density. We recruited 373 African ancestry family membe...

The major intermediate steps in the renin-angiotensin-vasoconstrictor feedback loop have been experimentally determined. The quantitative relationships between renal perfusion pressure, renin secretion, arterial renin activity, and systemic arterial blood pressure were determined in dogs in which the cardiovascular control loops of the central nervous system were eliminated by spinal cord destr...

1. A large dose of oestrogen elevated the blood pressure in male Westar rats. 2. Plasma renin substrate and renin activity increased significantly but plasma renin concentration was unchanged. 3. The increase in blood pressure induced by oestrogen was significantly reduced by salt loading, plasma renin concentration was suppressed and the increase in plasma renin activity was reduced. 4. The in...

The existence of renin in the adrenal gland of the mouse was determined by its enzymatic activity and by immunohistochemical techniques using monospecific antibodies to mouse submandibular gland renin. The adrenal gland of mouse was found to contain a very high level of renin significantly greater than other mouse tissues except for the kidney and submandibular gland. Also, the renin level in m...

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...

The renin-angiotensin system (RAS) is well studied for its regulation of blood pressure and fluid homeostasis, as well as for increased activity associated with a variety of diseases and conditions, including cardiovascular disease, diabetes, and kidney disease. The enzyme renin cleaves angiotensinogen to form angiotensin I (ANG I), which is further cleaved by angiotensin-converting enzyme to p...

1. Several commonly used preparations of human renin, including the International Reference Preparation (Renin Standard 68/356), were examined for the presence of contaminating proteinase activity by using a 14C-glycinated bovine haemoglobin substrate assay. 2. All of the human renin preparations tested cleaved haemoglobin even in the presence o di-isopropylfluorophosphate and ethylenediaminete...