粉防己碱对小鼠、家兔和豚鼠肠平滑肌的作用

目的　研究钙拮抗剂粉防己碱 (tetrandrine,Tet)对小鼠、家兔和豚鼠肠平滑肌的影响。方法　用小鼠胃肠推进运动法 ,家兔和豚鼠离体肠平滑肌标本。结果　 Tet(1 0～ 1 5 mg· kg-1,ig)对小鼠肠平滑肌运动无明显影响 ,Tet抑制家兔离体回肠自发性收缩 ,Tet(1 0 μmol·L-1)抑制氨甲酰胆碱诱导的豚鼠结肠带依内钙收缩 ,但不影响依外钙收缩。Tet浓度依赖性地使 KCl引起的豚鼠离体结肠带收缩量效曲线非平行右移 ,最大反应降低 ,p D2 为 4.0 1。结论　 Tet主要抑制肠平滑肌电压依赖性钙通道 (PDC) ,阻止 Ca2 + 通过 PDC,但对胃肠运动功能影响较小

The pharmacological effect of tetridrine on intestinal smooth muscles i n mice, rabbits and guinea-pigs

objective To Study the effects of tetridrine(Tet) on intestinal smooth muscles. Methods The effects of Tet on the intestinal smooth muscles derived from mice, rabbits and guinea-pigs were studied in vivo and in vitro. Result In vivo experiment, Tet(10～15 mg·kg -1, ig) showed no significant inhibition on the advance movement of mouse intestinal smooth muscles(P>0 05). Tet could inhibit the spontaneous contraction of isolated ileum derived from rabbits. Tet(10 μmol·L -1) showed pronounced inhibitions on intracellar calcium-dependent contraction of the isolated guine-pig taenia coli induced by carbachol(car). But showing no effects on the extraceuar calcium-dependent contractions induced by car. In the isolated guinea-pigs teania coli, Tet non-parallelly shifted the KCl cumulative dose response curves to the right with a lower maximal response. PD 2 value was shown to be 4 01. Conclusion Tet primarily inhibited the potential dependent channel(PDC) of intestinal smooth muscle and prevented the influx of Ca 2+ through PDC. Tet showed no significant inhibition on the gastric intestinal movement within dose exerting cardiovascular effect.