title: Role of adrenal renin-angiotensin system in the control of aldosterone secretion in sodium-restricted rats.
abstract: This study examined the effect of the pharmacological manipulation of adrenal renin-angiotensin system (RAS) on aldosterone secretion from in situ perfused adrenals of rats kept on a normal diet and sodium restricted for 14 days. Neither the angiotensin-converting enzyme inhibitor captopril nor the nonselective angiotensin II receptor antagonist saralasin and the AT(1) receptor-selective antagonist losartan affected basal aldosterone output in normally fed rats. In contrast, they concentration dependently decreased aldosterone secretion in sodium-restricted animals, with maximal effective concentration ranging from 10(-7) to 10(-6) M. Captopril (10(-6) M), saralasin (10(-6) M), and losartan (10(-7) M) counteracted aldosterone response to 10 mM K(+) in sodium-restricted rats but not in normally fed animals. Collectively, these findings provide evidence that adrenal RAS plays a role in the regulation of aldosterone secretion, but only under conditions of prolonged stimulation of zona glomerulosa probably leading to overexpression of adrenal RAS.
authors.affiliation: Section of Anatomy, Department of Human Anatomy and Physiology, University of Padua, I-35121 Padua, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Mazzocchi
authors.forename: L K
authors.initials: LK
authors.lastname: Malendowicz
authors.forename: A
authors.initials: A
authors.lastname: Markowska
authors.forename: G
authors.initials: G
authors.lastname: Albertin
authors.forename: G G
authors.initials: GG
authors.lastname: Nussdorfer
mesh_terms: D000311:Adrenal Glands / Q000502:physiology*; D000450:Aldosterone / Q000378:metabolism*; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D002216:Captopril / Q000494:pharmacology; D004039:Diet, Sodium-Restricted; D019808:Losartan / Q000494:pharmacology; D008297:Male; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D012084:Renin-Angiotensin System / Q000502:physiology*; D012504:Saralasin / Q000494:pharmacology
chemical_list: D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D000450:Aldosterone; D002216:Captopril; D012504:Saralasin; D019808:Losartan; D011188:Potassium