Endothelial dysfunction in pulmonary arteries of patients with mild COPD

L908–L913, 1998.—To investigate whether endothelial dys-function of pulmonary arteries (PA) is present in patients with mild chronic obstructive pulmonary disease (COPD) and to what extent it is related to the morphological abnormalities of PA, we studied 41 patients who underwent lung resection. Patients were divided into the following groups: nonsmokers (n 5 7), smokers with normal lung function (n 5 13), and COPD (n 5 21). Endothelium-dependent relaxation mediated by nitric oxide was evaluated in vitro in PA rings exposed to cumulative concentrations of acetylcholine (ACh) and ADP. Structural abnormalities of PA were assessed morphometri-cally. PA of COPD patients developed lower maximal relax-ation in response to ADP than both nonsmokers and smokers (P, 0.05 each) and a trend to reduced relaxation in response to ACh (P 5 0.08). Maximal relaxation to ADP correlated wit