A Protective Factor for Blood Vessels

Abstract—Adrenomedullin,(AM) is a vasodilator peptide having a wide range of biological actions such as reduction of oxidative stress and inhibition of endothelial cell apoptosis. The AM gene is expressed in vascular walls, and AM was found to be secreted from cultured vascular endothelial cells, smooth muscle cells, and adventitial fibroblasts. Plasma AM levels in patients with arteriosclerotic vascular diseases are elevated in possible association with the severity of the disease. When administered over a relatively short period, AM dilates blood vessels via an endothelium-dependent or independent mechanism. Experiments in vitro have shown that AM exerts multiple actions on cultured vascular cells, which are mostly protective or inhibitory against vascular damage,and progression of arteriosclerosis. Either prolonged infusion or overexpression of AM suppressed intimal thickening, fatty streak formation, and perivascular hyperplasia in rodent models,for vascular remodeling,or atherosclerosis. Intimal thickening induced by periarterial cuff was more