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Control of renin secretion from kidneys with renin cell hyperplasia.

Authors :
Kurt, Birgül
Karger, Christian
Wagner, Charlotte
Kurtz, Armin
Source :
American Journal of Physiology: Renal Physiology. Feb2014, Vol. 306 Issue 3, pF327-F332. 6p.
Publication Year :
2014

Abstract

In states of loss-of-function mutations of the renin-angiotensin-aldosterone system, kidneys develop a strong hyperplasia of renin-producing cells. Those additional renin cells are located outside the classic juxtaglomerular areas, mainly in the walls of preglomerular vessels and most prominently in multilayers surrounding afferent arterioles. Since the functional behavior of those ectopic renin cells is yet unknown, we aimed to characterize the control of renin secretion from kidneys with renin cell hyperplasia. As a model, we used kidneys from mice lacking aldosterone synthase (AS-/- mice), which displayed 10-fold elevations of renin mRNA and plasma renin concentrations. On the absolute level, renin secretion from isolated AS-/- kidneys was more than 10-fold increased over wild-type kidneys. On the relative level, the stimulation of renin secretion by the β-adrenergic activator isoproterenol or by lowering of the concentration of extracellular Ca2+ was very similar between the two genotypes. In addition, the inhibitory effects of ANG II and of perfusion pressure were similar between the two genotypes. Deletion of connexin40 blunted the pressure dependency of renin secretion and the stimulatory effect of low extracellular Ca2+ on renin secretion in the same manner in kidneys of AS-/- mice as in wild-type mice. Our findings suggest a high degree of functional similarity between renin cells originating during development and located at different positions in the adult kidney. They also suggest a high similarity in the expression of membrane proteins relevant for the control of renin secretion, such as β1-adrenergic receptors, ANG II type 1 receptors, and connexin40. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
1931857X
Volume :
306
Issue :
3
Database :
Academic Search Index
Journal :
American Journal of Physiology: Renal Physiology
Publication Type :
Academic Journal
Accession number :
94431940
Full Text :
https://doi.org/10.1152/ajprenal.00536.2013