Adrenomedullin Stimulates Cyclic AMP Formation in Rat Vascular Smooth Muscle Cells

• DOI: 10.1006/bbrc.1994.1496
• Publication Date: 2002-09-16T10:51:07Z
• Authors: Y. Ishizaka; Y. Ishizaka; M. Tanaka; K. Kitamura; K. Kangawa; N. Minamino; H. Matsuo; T. Eto
• Keywords: Male; 0301 basic medicine; Analysis of Variance; Binding Sites; Calcitonin Gene-Related Peptide; Binding, Competitive; Rats, Inbred WKY; Muscle, Smooth, Vascular; Rats; Adrenomedullin; Kinetics; 03 medical and health sciences; Cyclic AMP; Animals; Humans; Peptides; Antihypertensive Agents; Aorta; Cells, Cultured

A newly identified human peptide, adrenomedullin (AM) increased cAMP levels with dose and time dependencies in a manner similar to that of human calcitonin gene-related peptide (CGRP) in rat vascular smooth muscle cells (VSMC). The EC50 value of human AM is 2 x 10(-8) M which is slightly higher than that of CGRP (8.5 x 10(-9) M). In a receptor binding assay for AM in rat VSMC, the binding of [125I] AM was competitively inhibited by human AM, but not by human CGRP. Thus, AM is thought to increase intracellular cAMP in rat VSMC via its specific receptor to evoke vasodilation.