Medeiros Y S, Torres R C, Calixto J B
Coordenadoria Especial de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, Brasil.
Braz J Med Biol Res. 1989;22(1):97-101.
The contractile effects of histamine (His), PAF-acether (PAF) and acetylcholine (Ach) were analyzed in tracheal rings from normal and ovalbumin-sensitized (OAS) guinea pigs. Although maximal responses to all agonists were enhanced in preparations from OAS guinea pigs, only the EC50 of Ach was significantly decreased. Previous treatment with 1 microM indomethacin (IND) or 10 microM quinacrine (QUIN) markedly displaced the dose-response curves for Ach on OAS preparations to the left, whereas the EC50 of His was only increased by QUIN. PAF-responses, however, were completely abolished by IND in preparations from both sensitized and unsensitized animals. These results indicate that ovalbumin sensitization significantly affects the tracheal response to Ach, His and PAF, an effect that appears to be mediated by arachidonic acid metabolites.
在正常豚鼠和卵清蛋白致敏（OAS）豚鼠的气管环中分析了组胺（His）、血小板活化因子（PAF）和乙酰胆碱（Ach）的收缩效应。尽管在OAS豚鼠的标本中对所有激动剂的最大反应均增强，但只有Ach的半数有效浓度（EC50）显著降低。预先用1μM吲哚美辛（IND）或10μM喹吖因（QUIN）处理可使OAS标本上Ach的剂量反应曲线明显左移，而His的EC50仅被QUIN升高。然而，在致敏和未致敏动物的标本中，PAF反应均被IND完全消除。这些结果表明，卵清蛋白致敏显著影响气管对Ach、His和PAF的反应，这种效应似乎由花生四烯酸代谢产物介导。
