花椒毒酚对家兔离体回肠的作用

Effect of Xanthnotoxol on Contractility of Isolated Rabbit Ileum

目的 :研究花椒毒酚对家兔离体回肠平滑肌的作用及其与Ca2 +的关系。方法 :采用常规回肠离体标本运动的实验方法。结果 :花椒毒酚 (XT)、维拉帕米 (Ver)可剂量依赖性地抑制次大剂量ACh ,5 HT所致的家兔离体回肠平滑肌收缩 ,非竞争性拮抗CaCl2 累积量 效曲线 ,pD2 ′分别为 4.6 9± 0 .0 3 ,6 .35± 0 .10。XT 10 μmol·L-1,Ver 0 .0 6 μmol·L-1可抑制ACh诱导的依内钙性收缩。XT 10 0 μmol·L-1尚可抑制ACh诱导的依外钙性收缩 ,但Ver 0 .6 μmol·L-1对此相收缩没有影响。结论 :XT具有钙拮抗作用 ,其作用方式不完全相同于Ver。

Objective: To study the effects of Xanthnotoxol on contractility of isolated rabbit ileum and its relationship with Ca 2+ . Method: Routime experimental methods for isolated ileum were adopted. Result: Xanthnotoxol (XT) and Verapamil (Ver) inhibited the contraction of iso lated rabbit ileum smoth muscle induced by submaximal concentrations of acetylcholine (ACh) and serotonim (5 TH), with a IC 50 value (μmol·L -1 ) of 10.495±1.521,0.428±0.001and 18.132±1.627,0.249±0.003,respectively. XT and Ver inhibited the contraction induced by Ca 2+ after high K + depolorization and for noncompetitively antagonist CaCl 2 cumulative dose-response curve, the pD' 2 value was 4.69±0.03 and 6.35±0.10, respectively. XT (10μmol·L -1 )and Ver(0.06μmol·L -1 )inhibited the contraction induced by ACh in Ca 2+ -free medium, while XT (100μmol·L -1 )but not Ver(0.6μmol·L -1 ) inhibited the extracellar Ca 2+ -dependent contraction induced by ACh. Conclusion: XT has a calcium antagonistic effect which was not similar to that of Ver. [