Ono T, Motoyama Y, Sakai S, Yoneda J, Kumada S
Jpn J Pharmacol. 1979 Dec;29(6):865-75. doi: 10.1254/jjp.29.865.
The effects of PGE2 and PGF2 alpha on the tonus of isolated guinea-pig tracheal chain were investigated and compared with those of histamine and acetylcholine. PGE2 reduced tonus in normal resting state, but elevated tracheal tonus reduced by aspirin. Such PGE2-induced contractions did not exceed the initial resting tonus, and the magnitude and duration of the contractions progressively diminished with increase of PGE2 concentrations. Aspirin produced neither relaxation nor contraction in the presence of a low dose of PGE2. Unlike PGE2, PGF2 alpha produced a dose-related contraction in the normal tracheal chain, and the contractile response to PGF2 alpha was markedly potentiated by aspirin. In the presence of PGF2 alpha, aspirin no longer produced tracheal relaxation but produced a dose-related contraction. The contractile effect of histamine but not of acetylcholine was also potentiated by aspirin, but there was a slight difference between PGF2 alpha and histamine in that the potentiation of action of PGF2 alpha by aspirin was more easily diminished by PGE2. These results suggest that PGE2 plays an important role in the maintenance of the resting tonus of the isolated guinea-pig tracheal chain, and in large doses it also acts as a tracheal relaxant and attenuates the tracheal responses to PGF2 alpha and histamine.
研究了前列腺素E2（PGE2）和前列腺素F2α（PGF2α）对离体豚鼠气管链张力的影响，并与组胺和乙酰胆碱的作用进行了比较。PGE2在正常静息状态下可降低张力，但能使因阿司匹林降低的气管张力升高。这种由PGE2诱导的收缩不超过初始静息张力，且随着PGE2浓度的增加，收缩的幅度和持续时间逐渐减小。在低剂量PGE2存在的情况下，阿司匹林既不产生舒张也不产生收缩作用。与PGE2不同，PGF2α在正常气管链中产生剂量相关的收缩，且阿司匹林可显著增强对PGF2α的收缩反应。在PGF2α存在的情况下，阿司匹林不再产生气管舒张作用，而是产生剂量相关的收缩。阿司匹林也能增强组胺而非乙酰胆碱的收缩作用，但PGF2α和组胺之间存在细微差异，即阿司匹林对PGF2α作用的增强更容易被PGE2减弱。这些结果表明，PGE2在维持离体豚鼠气管链的静息张力中起重要作用，并且大剂量时它还可作为气管舒张剂，减弱气管对PGF2α和组胺的反应。
