目的考察柚皮苷对正常及多种致痉剂诱导的豚鼠气管平滑肌收缩功能的影响及其作用机制。方法采用离体气管恒温灌流的方法,取豚鼠气管,在K-H液中制备豚鼠离体气管环,在其静息张力状态下以及用乙酰胆碱(Ach)、组胺(His)、氯化钙(Ca Cl2)、无钙时Ach诱导细胞内钙释放和高钙时诱发细胞外钙内流条件下,通过BL-420S生物机能实验系统测定其张力的变化,考察柚皮苷对离体豚鼠气管平滑肌张力的影响。结果柚皮苷低剂量浓度(0.0172~0.5504)mmol·L^-1时,对静息状态下的豚鼠离体气管平滑肌有一定的收缩作用,高剂量浓度(0.5504~1.3780)mmol·L^-1时舒张气管平滑肌,且呈剂量依赖性;使致痉剂Ach、His、Ca Cl2收缩豚鼠离体气管平滑肌的量效曲线非平行性右移,最大效应降低;抑制加入高钙后引发细胞外钙内流导致的收缩。结论柚皮苷舒张气管平滑肌作用机制可能与抑制豚鼠气管平滑肌上M受体、H1受体和阻断Ca2+通道从而抑制细胞Ca2+内流有关。
Objective To investigate the effects of naringin on the contraction of isolated tracheal smooth muscle of guinea pigs induced by resting tension or spasmogens, and to explore its therapeutic mechanism. Methods Isolated tracheal thermostatic perfusion method was used. The guinea pig tracheal smooth muscle was isolated in the K-H solution. Under the resting tension or stimulated by acetylcholine(Ach),histamine (His),calcium chloride(CaCl2), calcium-free Ach-induced intracellular Ca2+ releasing, or extracellular Ca2+ influx at the high concentration of Ca2+, the tension of isolated guinea pig tracheal smooth muscle was observed by BL-420S biological function experiment systems, and the effect of naringin on the tension was evaluated. Results Naringin at the concentrations of 0.0172~0.5504 mmol·L^-1 could induce the contraction of isolated trachea at resting state, and when at the concentrations of 0.5504~1.3780 mmol·L^-1, naringin could induce the relaxation of the isolated trachea in concentration-dependent manner. Naringin could result into the non-parallelled rightward move and the decline of maximal effect of the cumulative concentration-response curve of Ach, His or Cacl2, and could counteract the contraction induced by extracellular Ca2+ influx. Conclusion Naringin could relax tracheal smooth muscle by acting on M-receptor and histamine receptor and blocking Ca2+passage,thus inhibiting extracellular Ca2+influx.