Regulation of calcium current by emodin in guinea pig gallbladder smooth muscle / 中国药理学通报

ABSTRACT

Aim To investigate the effects of emodin on the contraction of gallbladder smooth muscle(GBSM)and the L-type calcium current in GBSM cells.Methods Gallbladder muscle strips were obtained from adult guinea pigs and the resting tension was recorded.Gallbladder smooth muscle cells were isolated by enzymatic digestion,and calcium current was recorded by the whole-cell patch clamp method.Results Emodin-induced contraction of GBSM was significantly attenuated by pretreatment with nifedipine.Emodin increased the L-type calcium current in a dose-dependent manner.When 10 ?mol?L-1 emodin was applied to GBSM cells,the amplitude of L-type calcium current at +10 mV was enhanced by(45.2?2.26)%.In the presence of PKC inhibitor,staurosporine,emodin did not significantly affect the calcium current.Conclusion Emodin enhances L-type calcium current via PKC-dependent pathway and promotes gallbladder contraction.