ADRENOMEDULLIN AND CALCITONIN-GENE-RELATED PEPTIDE IN THE RAT ISOLATED KIDNEY AND IN THE ANESTHETIZED RAT - IN-VITRO AND IN-VIVO EFFECTS

The effects of adrenomedullin and calcitonin gene-related peptide (CGR P) were compared in the rat isolated perfused kidney and in the anaest hetised rat. Adrenomedullin and CGRP both elicited concentration-depen dent vasodilator responses from perfused kidneys (adrenomedullin was l ess potent than CGRP). These responses were blocked by CGRP-(8-37) (1 mu M). Adrenomedullin and CGRP elicited dose-dependent hypotension in anaesthetised rats (adrenomedullin was less potent than CGRP). The hyp otensive responses to CGRP, but not those to adrenomedullin, were anta gonized by CGRP-(8-37) (12 nmol/kg/min). These studies indicate that t he in vivo response to adrenomedullin may be mediated through CGRP-(8- 37) insensitive receptors.