枳实提取液对豚鼠心室肌细胞L型钙电流的影响

Effect of citrus aurantium extract on L-type calcium currents in ventricular myocytes of single guinea pigs

目的 :探讨枳实提取液 (CAE)对豚鼠心室肌细胞膜L型钙通道电流 (ICa L)的影响。方法 :用酶解法分离单个心室肌细胞 ,采用全细胞膜片钳技术 ,观察枳实提取液对豚鼠心室肌细胞膜ICa L的影响。结果 :①CAE(4×10 3 ,2× 10 2 ,4× 10 2 ,1× 10 1)g/ml增大ICa L,增加率分别为 15 .89%,2 9.0 1%,5 2 .0 3%和 5 9.76 %(P <0 .0 5 )。②CAE 2× 10 1g/ml和 4× 10 1g/ml分别可使峰值ICa L减少 17.33%和 30 .0 9%(P <0 .0 5 )。CAE只改变电流幅度 ,不改变I V曲线形状。结论 :低浓度CAE ,可浓度依赖性的增大豚鼠心室肌细胞L型钙电流 ,有促进钙通道开放的作用。高浓度CAE ,可抑制心室肌细胞L型钙电流 ,有抑制钙通道开放的作用。

Objective To determine the effect of citrus aurantium extract (CAE) on L-type calcium currents (I Ca-L)in ventricular myocytes of guinea pigs. Methods Single myocytes were dissociated by enzymatic dissociation method. The whole-cell patch-clamp recording technique was used to record the change of calcium current after the administration of CAE. Results ① CAE 4×10 -3, 2×10 -2, 4×10 -2,and 1×10 -1 g/ml increased the I Ca-L by 15.89%, 29.01%, 52.03% and 59.76% (P<0.05), respectively. ② CAE 2×10 -1 and 4×10 -1 g/ml decreased the I Ca-L by 16.61% and 30.87% (P< 0.05), respectively. CAE changed the I Ca-L significantly, but did not change the shape of I-V curves.Conclusions CAE 4×10 -3 ～ 1×10 -1 g/ml can increase the L-type calcium current in guinea pig ventricular myocytes significantly in a concentration-dependent manner, and promote the opening of calcium channel. CAE 2×10 -1～4×10 -1g/ml may inhibit the L-type calcium channels of ventricular myocytes, and depress the opening of calcium channel.