Halothane-induced relaxation of vascular smooth muscle: a possible contribution of increased cyclic GMP formation

Halothane (0.75 to 2.25%) dose-dependently relaxed the vascular smooth muscle of endothelium-denuded rat aortae previously contracted with KCl, and the relaxing effect was not significantly affected by indomethacin nor dexamethasone, but partly inhibited by methylene blue. The cyclic GMP levels were increased by treatment with halothane (2.25%). It was suggested that halothane-induced relaxation of vascular smooth muscle is partly mediated by cyclic GMP formation.