Selective activation of excitation-contraction coupling pathways by ET_A and ET_B receptors in guinea-pig tracheal smooth muscle

摘要

1. Signalling events responsible for endothelin_A (ET_A) and ET_B receptor-induced contraction were examined in epithelium-denuded guinea-pig tracheal smooth muscle strips. Selective stimulation of each subtype was achieved by a combination of ET-1 (100 nm) and ET_A and ET_B receptor-selective antagonists, BQ-123 (10μM) and BQ-788 (3μM), respectively. 2. Both ET_A and ET_B receptors induced long-lasting contraction that was totally dependent on Ca~2+ influx.