小裂芽梅衣对兔离体肠平滑肌的舒张作用及其机制

Relaxant effect of Parmelia nimandairana on contraction of intestinal smooth muscle of rabbit in vitro and its mechanism

采用兔离体肠肌试验,应用BL-420E生物机能实验系统比较小裂芽梅衣对正常肠肌及乙酰胆碱、氯化钡、组胺所致肠平滑肌运动的影响。应用IP3受体阻断剂肝素、肌浆网ryanodine受体阻断剂钌红、一氧化氮合酶抑制剂左旋硝基精氨酸甲酯,探讨小裂芽梅衣对兔离体肠平滑肌的作用机制。结果表明,小裂芽梅衣可浓度依赖性抑制兔小肠平滑肌的收缩,且对乙酰胆碱、氯化钡、组胺诱导的肠平滑肌收缩有明显抑制作用(P<0.05)。肝素能显著增强小裂芽梅衣对兔小肠平滑肌运动的抑制作用(P<0.05),左旋硝基精氨酸甲酯和钌红能部分增强小裂芽梅衣对兔小肠平滑肌运动的抑制作用(P<0.01)。小裂芽梅衣乙醇提取物对兔小肠平滑肌收缩的抑制作用机制可能与增加NO浓度、抑制IP3受体和肌浆网ryanodine受体介导的内钙释放有关。

The influences of ethanol extract from Parmelia nimandairana on the spontaneous contraction of intestine and contractions induced by acetylcholine（ACh）, histamine（HA） and Ba Cl2 were observed by using BL-420 E biologic function analysis system, and the mechanism of Parmelia nimandairana was studied using inositol 1,4,5-trisphosphate（IP3） receptor antagonist heparin, ryanodine receptor antagonist ruthenium red and a nitric oxide synthase（NOS） inhibitor Nitro-L-arginine methyl ester. The results showed that the ethanol extract from Parmelia nimandairana could dose-dependently inhibit the spontaneous contraction of intestinal smooth muscle and significantly inhibit the amplitude and tension of intestinal smooth muscleinduced by ACh, HA and Ba Cl2（P〈0.05）. Parmelia nimandairana ethanol extract could inhibit the frequency, amplitude and tension of intestinal smooth muscle by the treatment of HP（50 mg/L）（P〈0.05）. L-NAME and RR could partially inhibit intestinal smooth muscle movement induced by Parmelia nimandairana ethanol extract（P〈0.01）. The inhibitory mechanism of ethanol extract from Parmelia nimandairana on intestinal smooth muscle contraction may be related to increase NO concentration in intestinal smooth muscle, and inhibit intracellular Ca2＋releasing via IP3 and ryanodine of sarcoplasmic reticulum.