Effects of verapamil and propranolol on bronchoconstriction induced by leukotriene D4 in the isolated perfused guinea pig lung

: The effects of verapamil and propranolol on the LTD4-induced bronchoconstriction were studied in the isolated, perfused and ventilated guinea pig lungs. Verapamil (4.10(-5) et 1, 2.10(-4)M.1(-1], a calcium antagonist, produces a significative inhibition of LTD4-induced bronchoconstriction. On the other hand, propranolol (10(-7)M and 10(-4)M) does not increase the constrictor effects of LTD4 in guinea-pig isolated lung. These first results obtained in guinea-pig lung, confirmed the protective effect of verapamil, effect previously demonstrated in vivo or in vitro by using lung parenchymal strips. We have also confirmed the difference between the in vivo and in vitro effects of propranolol.