抽象
在气道刺激后,速激素的纤毛刺激作用,物质P (SP),被认为是继发于粘液释放。我们假设SP也通过钙介导的过程诱导纤毛跳动频率(CBF)的微小增加。将健康人鼻上皮的毛刷纤毛细胞悬浮于组织培养液中,在无粘液环境中研究SP对这些细胞的急性作用。在一些准备中,CBF对SP反应的变化是通过一个基于视频的系统测量的。SP拮抗剂、维拉帕米钙离子通道阻滞和钙类似物镧对SP反应的影响也进行了测试。在其他的准备中,纤毛细胞预先加载Fura-2,一种能发出Ca2+离子荧光的染料,并监测细胞内Ca2+对SP的响应。SP (10(-9)-10(-6) M)瞬时增加CBF,并呈剂量依赖性,最大反应发生在10 min,但反应较小,最大增加8.9%。SP受体拮抗剂(D-pro2,D-trp7,9)-SP (10(-5) M)消除了这种作用。维拉帕米(10(-5)M)减弱了对SP (10(-7) M)的反应,而氯化镧(250微米)消除了它。磷酰胺(10(-6)M)对SP破坏的抑制也消除了CBF的短暂升高。 However, compared to SP alone, the combination of SP and phosphoramidon induced a novel delayed lanthanum-sensitive rise in CBF. In other experiments, SP (10(-7) M) induced a transient increase in free intracellular Ca2+ concentration (maximal rise 73%), which returned to baseline before the expected onset of the CBF response. We conclude that substance P induces either a transient or sustained increase in CBF dependent on the rate of destruction of this peptide around tachykinin receptors. These receptors are likely to be linked to lanthanum- and verapamil-sensitive pathways for the entry of Ca2+ into cells. The small magnitude of the rise in CBF makes its physiological role uncertain at present.