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 (CGRP) were compared in the rat isolated perfused kidney and in the anaesthetised rat. Adrenomedullin and CGRP both elicited concentration-dependent vasodilator responses from perfused kidneys (adrenomedullin was less 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 hypotensive responses to CGRP, but not those to adrenomedullin, were antagonized by CGRP-(8-37) (12 nmol/kg/min). These studies indicate that the in vivo response to adrenomedullin may be mediated through CGRP-(8-37) insensitive receptors.