ADRENOMEDULLIN AND CALCITONIN-GENE-RELATED PEPTIDE INHIBIT ALDOSTERONE SECRETION IN RATS, ACTING VIA A COMMON RECEPTOR

Adrenomedullin (ADM) and calcitonin gene-related peptide (CGRP) did no t affect either basal or ACTH-stimulated secretion of aldosterone and corticosterone by dispersed rat capsular and inner adrenocortical cell s, respectively. However, both peptides strongly depressed angiotensin -II (ANG-II)-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) recep tor antagonist; a complete reversal was obtained with a CGRP(8-37) Con centration of 10(-6) M. Our findings indicate that ADM and CGRP specif ically interfere with the intracellular mechanisms transducing the sec retagogue signal of ANG-II, and suggest that the ADM effect is mediate d by CGRP receptors.