左旋荷包牡丹碱对猪冠状动脉条收缩效应的影响

Effect of L-dicentrine on contractility of the sprips of porcine coronary artery

目的观察左旋荷包牡丹碱(L_dicentrine ,L_D)对K +、5_HT、Hist、Ca2 +引起的猪冠状动脉条收缩效应的影响。方法利用猪冠状动脉条的离体实验法,观察对其收缩的影响。结果L_D对K +、5_HT、Hist、Ca2 +诱发的猪冠状动脉平滑肌的收缩有显著的拮抗作用,量效曲线显示:L_D呈现非竞争性拮抗方式。在无Ca2 +液中,L_D能抑制5_HT诱发的猪冠状动脉收缩,说明5_HT对猪冠状动脉依赖细胞内Ca2 +所致的收缩有明显的抑制作用,而对外Ca2 +所致的收缩无明显的影响。结论L_D具有松弛猪冠状动脉条的作用 ,同时也提示冠状动脉平滑肌可能存在5_HT受体。

Aim & methods The antagonism of L-dicentrine to contraction of isolated porcine coronary artery strips induced by 5-HT KCl and Ca2+ was observed with U-135 electrophsiological recorder.Results The contractions induced by 5-HT KCl and Ca2+ after high K+ depolarization in the strips of porcine coronary artery were markediy inhibited by L-dicentrine.L-dicentrine significantly depressed maximal response and caused rightward displacement of the dose -response curve. Showing a non-competitive antagonism. In Ca2+ free solution,L-dicentrine inhibited 5-HT-induced contraction of porcine coronary artery,which is dependent on Ca2+ relesed from intracellular store. After Ca2+ concentration in bath solution was restored,L-dicentrine did not influence the contraction of porcine coronary artery depending on extracellular Ca2+.Conclusion L-D have significant relaxation on porcine coronary artery ,which possibly has 5-HT receptor and histamine receptor.