Atropine, Sodium Cromoglycate, and Thymoxamine in PGF2α-induced Bronchoconstriction in Extrinsic Asthma

Abstract

In six patients with extrinsic bronchial asthma the inhalation of prostaglandin (PG) F2α in a small dosage produced significant bronchoconstriction, whereas PGE2produced bronchodilatation. In these patients cholinergic blockade with atropine partially inhibited the PGF2α-induced bronchoconstriction, but the a-receptor-blocking drug thymoxamine and sodium cromoglycate did not. These results suggest that the effect of PGF2α is mediated through cholinergic receptors in the airways, and this effect is grossly exaggerated in asthma. The failure to inhibit PGF2α-induced bronchoconstriction with sodium cromoglycate and the observation of an inhibitory effect of sodium cromoglycate in both allergic and exercise asthma suggest that locally formed PGF2α may not be the main factor in the pathogenesis of bronchial asthma. © 1975, British Medical Journal Publishing Group. All rights reserved.