小檗碱对豚鼠心室肌细胞胞浆内游离钙离子浓度的影响

研究小檗碱对豚鼠心肌细胞胞浆 [Ca2 + ]i 的影响 .用酶解法分离单个豚鼠心肌细胞 ,Fluo- 3/AM标记胞浆内游离钙离子 ,激光扫描共聚焦显微镜实时测定胞浆 [Ca2 + ]i变化 .结果 ,小檗碱 1 -1 0 0 μmol· L-1对正常台氏液中静息状态细胞胞浆[Ca2 + ]i 无明显影响 ;小檗碱 1 μmol·L-1对 KCl30mmol·L-1引起的细胞外钙内流有抑制作用 ( P<0 .0 1 ) ,而小檗碱 1 0 0 μmol·L-1对细胞内钙库释放有强烈激动作用 ( P<0 .0 1 ) .结果提示在豚鼠心肌细胞上低浓度小檗碱即能抑制电压依赖性钙通道 ,而高浓度时又能激动细胞内钙库释放 .

Effect of berberine on the cytosolic calcium concentration in the single ventricular cell of guinea pig

To study the effect of berberine on the cytosolic ［Ca²⁺］_i of ventricular cells. Single cardiac myocytes of guinea-pig were isolated by an enzymatic technique and loaded with the Ca²⁺ indicator Fluo-3/AM. Fluorescence change was measured using a confocal microscope with 488 nm excitation from an argon ion laser. The results showed that the berberine (1, 10, 100 μmol·L^-1) had no effect on cytosolic ［Ca²⁺］_i of normal resting cells in normal Tyrode′s solution; berberine 1 μmol·L^-1 significantly inhibited the Ca²⁺ influx induced by KCl 30 mmol·L^-1, fluorescence peak value was 391±23 vs 492±66 50 s after KCl (P<0.01), while berberine 100 μmol·L^-1 had a strong stimulating effect on the release of intracellular Ca²⁺ store fluorescence peak value was much higher than control group (1287±337 vs 531±43) 20 s after administration (P<0.01). The results suggest that berberine not only inhibit L-type voltage-dependent Ca²⁺ channel, but also stimulate the release of intracellular Ca²⁺ stores in heart cells at higher concentration.