Barnes P J, Grandordy B M, Page C P, Rhoden K J, Robertson D N
Br J Pharmacol. 1987 Apr;90(4):709-15. doi: 10.1111/j.1476-5381.1987.tb11224.x.
An intravenous infusion of platelet activating factor (Paf) in the guinea-pig elicits an increase in bronchial responsiveness to the spasmogens, histamine and bombesin. Airways obstruction induced by bombesin in Paf-treated animals is poorly reversed by isoprenaline compared to comparable airways obstruction induced by bombesin in vehicle-treated animals. Isoprenaline induced a comparable dose-related relaxation in vitro of tracheal smooth muscle isolated from Paf- and vehicle-treated animals. No change in beta-adrenoceptor numbers or binding affinity was observed in lungs removed from Paf-treated animals in comparison with those from vehicle-treated animals, or after direct incubation with Paf in vitro. The reduced bronchodilator responsiveness to isoprenaline in Paf-treated animals is not related to changes in pulmonary beta-adrenoceptor function. These results suggest that non-spasmogenic elements may contribute to airways obstruction induced in hyper-responsive animals.
给豚鼠静脉输注血小板活化因子(Paf)会导致支气管对痉挛原、组胺和蛙皮素的反应性增加。与在给予赋形剂处理的动物中由蛙皮素诱导的气道阻塞相比,在给予Paf处理的动物中由蛙皮素诱导的气道阻塞用异丙肾上腺素逆转的效果较差。异丙肾上腺素在体外对从给予Paf和赋形剂处理的动物分离出的气管平滑肌诱导出相当的剂量相关舒张作用。与给予赋形剂处理的动物相比,在给予Paf处理的动物取出的肺中,或在体外与Paf直接孵育后,未观察到β-肾上腺素能受体数量或结合亲和力的变化。给予Paf处理的动物对异丙肾上腺素的支气管扩张反应性降低与肺β-肾上腺素能受体功能的变化无关。这些结果表明,非痉挛性因素可能导致高反应性动物的气道阻塞。