Differential activity of leukotrienes upon human pulmonary vein and artery

Abstract

Responses to leukotrienes B 4, C 4, D 4 and E 4 were examined in human pulmonary artery and pulmonary vein preparations from surgical specimens. Leukotrienes C 4 (LTC) and D 4 (LTD) were potent contractants of pulmonary vein over the dose range of 10 −10M to 10 −6M, whereas they produced minimal contractions of human pulmonary artery only at concentrations of 10 −8M or greater. Leukotriene E 4 was less potent than LTC or LTD, and leukotriene B 4 (LTB) at concentrations up to 10 −6M had no effect upon either pulmonary veins or pulmonary arteries. Contractions of pulmonary vein by LTD were inhibited in a competitive manner by FPL 55712. Dose response characteristics of LTD and inhibition by FPL 55712 were similar for pulmonary venous and bronchial smooth muscle. We conclude that pulmonary vein smooth muscle has leukotriene receptors comparable to those of bronchial smooth muscle whereas pulmonary artery does not.