Adrenomedullin and calcitonin gene-related peptide inhibit aldosterone secretion in rats, acting via a common receptor

Abstract

Adrenomedullin (ADM) and calcitonin gene-related peptide (CGRP) did not affect either basal or ACTH-stimulated secretion of aldosterone and corticosterone by dispersed rat capsular and inner adrenocortical cells, respectively. However, both peptides strongly depressed angiotensin-II (ANGII) stimulated aldosterone production by capsular cells; the minimal effective concentration was 10 −7 M. The inhibitory effect of both ADM and CGRP was reversed by CGRP 8–37, a specific CGRP 1 receptor antagonist, a complete reversal was obtained with a CGRP 8–37 concentration of 10 −6 M. Our findings indicate that ADM and CGRP specifically interfere with the intracellular mechanisms transducing the secretagogue signal of ANG-II, and suggest that the ADM effect is mediated by CGRP receptors.