Plasma endothelin-1 levels in patients with peripheral arterial occlusive disease at different Fontaine's stages

Endothelin-1 (ET-1) is a potent vasoconstrictor and mitogenic peptide produ ced and secreted by endothelial cells, which can play a potential role in t he development of atherosclerosis and in the pathophysiology of extreme vas oconstriction of various diseases. Methods. To assess plasma endothelin-l (ET-1) concentrations in patients wi th peripheral arterial occlusive disease (PAOD) at different,Fontaine's sta ges, we measured plasma ET-1 by radioimmunoassay in 14 stage II PAOD patien ts (12 men, 2 women; mean age 59.5+/-3.4 years) and in 10 stage III-IV PAOD patients (8 men, 2 women, mean age 61.2+/-3.3 years), Ten normal subjects (8 men, 2 women, mean age 58.1+/-7.2 years) were considered as controls. Results. Mean (+/-SD) plasma ET-1 levels, as measured by radioimmunoassay, were significantly greater in stage II and stage III-IV PAOD patients than in control subjects (4+/-0.4 and 5+/-0.4 pmol/L vs 2.5+/-0.6 pmol/L, respec tively, p<0.001), Furthermore, plasma levels of ET-1 in stage III-IV patien ts were significantly higher than in stage II patients (p<0.01), A signific ant correlation was found between plasma ET-1 levels and number of the arte rial obstructive lesions in PAOD patients (r=0.698; p<0.0001), No significa nt correlation was found between plasma ET-1 concentrations and pain-free w alking distance (r=-0.279, p=0.333, in stage II patients; r=0.137, p=0.705, in stage III-IV patients), and between plasma ET-1 levels and ankle/arm pr esser index (r=0.032, p=0.913, in stage II patients; r=0.149, p=0.681, in s tage III-IV patients) in the PAOD patients, Conclusions. Raised plasma ET-1 could be a sensible marker both of endothel ial damage and disease extension. It could also promote the progression of atherosclerotic plaques and enhance the microvascular resistance in these p atients.