On the basis of its nucleotide homologies with calcitonin gene-related peptide (CGRP), calcitonin, and amylin, adrenomedullin is considered to be the fourth CGRP family member. TheAdm gene contains four exons panning approximately 2 and codes for two biologically active peptides: oadrenomedullin N-terminal 20 peptide(PAMP) Recent studies to identify the receptors for A and CGRP have led to the discovery of a mechanism of signal transduction kb whereby a series of single transmembrane spanning receptor activity-modifying proteins(RAMPs) interact with a common receptor to impart specificity of binding for either Adm or CGRP(3). The differential expression of the receptor activity-modifying proteins may dictate the sites of function of the twe ligands