Kv和BK_(Ca)通道阻断剂对家兔离体Oddi括约肌肌环张力的作用及芍药甙的调控作用

Effect of blockers of Kv and BKCa channels on muscle tension of rabbit oddi sphincter in vivo and the regulatory effect of paeoniflorin

目的探讨电压依赖性钾通道(Kv)、大电导钙激活钾通道(BKCa)阻断剂对家兔离体Oddi括约肌(SO)肌环张力的作用及中药芍药的有效成分芍药甙对其调控作用。方法制备离体兔Oddi括约肌肌环标本,放置于平滑肌恒温灌流浴槽中,观察Kv通道阻断剂4-aminopyridine(4-AP)、BKCa通道阻断剂tetraethylammonium chloride(TEA)对家兔离体SO肌环的收缩作用;观察芍药甙对4-AP和TEA引起的收缩作用的影响。结果 4-AP、TEA均可以引起SO肌环收缩,且随4-AP、TEA浓度增加,收缩程度也在增强。4-AP和TEA对SO肌环的收缩作用可以被芍药甙抑制。结论在离体条件下,Kv通道和BKCa通道对维持SO细胞的静息膜电位起主要作用。芍药甙可能通过对Kv通道和BKCa通道的调控,实现了对SO细胞的舒张反应。

Objective It is to investigate the effect of blockers of voltage-gated potassium channels （ Kv） , large-conduct-ance calcium-activated potassium channel （ BKCa） on sphincter of Oddi （ sphincter of Oddi , SO） from rabbits muscle ten-sion rings, and to explore the regulatory effect of the active ingredients of traditional Chinese medicine paeoniflorin on them . Methods Isolated rabbit sphincter of Oddi muscle rings specimens were prepared and placed on the smooth muscle perfusion bath temperature to observe the contraction effect of Kv channel blocker 4-aminopyridine （4-AP）, BKCa channel blocker tetraethylammonium chloride（ TEA） on isolated rabbit SO muscle rings and the effects of paeoniflorin on the contraction effects induced by 4-AP and TEA.Resul ts 4-AP and TEA both could cause contraction of SO muscle rings , with the the concen-trations increased , the contraction degrees increased .The contraction effects induced by 4-AP and TEA could be inhibited by paeoniflorin .Conclusion In vitro condition , Kv channel and BKCa channel play a major role in the maintenance of sphincter of Oddi resting membrane potential of cells .Paeoniflorin may influence the relaxant responses of SO cells possibly through the regulation of Kv and BKCa channels .