摘要
内皮素(et)是一类新型调节肽,多种证据表明内皮素在调节肺功能中发挥重要作用。在人类肺中发现了两种内皮素受体,ETA和ETB,根据最近的研究,一种非ETA受体似乎介导了大型人类支气管的收缩。一些研究强调小支气管在气道疾病发病机制中的重要性。在本论文中,采用了改进的方法,使体外研究能够对直径小于0.5-1.0 mm的小支气管进行研究。使用新的方法,我们试图进一步描述这种受体。支气管树远端小支气管取自15例肺癌患者的肺组织。解剖并切成环段,记录环段等距张力。ET-1, ET-2和ET-3引起人小支气管强烈的浓度依赖性收缩。基本上,这三个肽是相等的,几乎相同的最大响应。在再次使用时,他们都表现出相同的快速耐受性,达到最初收缩的一半。 Comparative analysis of IRL 1620, a selective ETB receptor agonist, revealed that the effect of the ETB agonist was, in all respects, similar to the responses induced by the ETs. PD 145065, a combined ETA/ETB receptor antagonist competitively inhibited the contractions induced by IRL 1620, whereas FR139317, a selective ETA receptor antagonist, was without effect. In conclusion, the present study shows that accurate measurements can be made in vitro on small human bronchi and all present data are in favour of an ETB receptor mediating endothelin-induced contraction of human bronchi smaller than 1.0 mm.