Raised plasma adrenomedullin in patients with systemic sclerosis complicated by pulmonary hypertension

Open Access
Publisher Website
Google Scholar
Abstract
Adrenomedullin is a hypotensive peptide newly found in human pheochromocytoma tissue.1 The peptide comprises 52 amino acids with an intramolecular disulphide bond. The mRNA of adrenomedullin has been detected in normal adrenal medulla, heart, kidney, and lung. Adrenomedullin is produced in endothelial cells, vascular smooth muscle cells, and fibroblasts.2Adrenomedullin receptors are expressed in both vascular smooth muscle cells and vascular endothelial cells. Adrenomedullin has a vasorelaxant effect, antagonising the vasospastic effect of endothelin-1 and seems to be implicated in the physiological and pathological control of circulation. Through multiple biological effects in the circulatory system, adrenomedullin appears to reduce plasma volume and blood pressure, thereby protecting the cardiovascular system.3Furthermore, adrenomedullin regulates not only vascular tonus but also vascular function through the autocrine/paracrine system, stimulating cAMP formation in a dose dependent manner,3 and exerting an anti-inflammatory effect by inhibiting the production of a chemoattractant from alveolar macrophages.4 Systemic sclerosis (SSc) is a chronic disease of unknown cause characterised by vascular changes and fibrosis of the skin and the visceral organs. Major complications of SSc …