Human Isolated Bronchial Smooth Muscle Contains Functional Ryanodine /Caffeine-sensitive Ca-Release Channels

摘要

Human bronchial smooth muscle (HBSM) contraction is implicated in a variety of respiratory diseases, including asthma, Yet, the pres - ence of an operative calcium-induced calcium release (CICR) mech - anism, identified in various smooth muscles, has not been estab - lished in HBSM. We therefore studied Ca-releasign mechanisms in HBSM obtained at thoracotomy with special attention to ryano - Dine-sensitive receptor channels (RyRs). In freshly isolated bron - Chial myocytes, ryanodine (0.5 to 50 μm) and caffeine (1 to 25 mM) induced transient increases in the cytoplasmic calcium con - centration ([Ca~2])