[Effect of Citrus aurantium extract on L-type calcium currents in ventricular myocytes of single guinea pigs].

OBJECTIVE

To determine the effect of citrus aurantium extract (CAE) on L-type calcium currents (ICa-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 x 10(-3), 2 x 10(-2), 4 x 10(-2), and 1 x 10(-1) g/ml increased the ICa-L by 15.89%, 29.01%, 52.03% and 59.76% (P < 0.05), respectively. 2. CAE 2 x 10(-1) and 4 x 10(-1) g/ml decreased the ICa-L by 16.61% and 30.87% (P < 0.05), respectively. CAE changed the ICa-L significantly, but did not change the shape of I-V curves.

CONCLUSIONS

CAE 4 x 10(-3)-1 x 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 x 10(-1)-4 x 10(-1) g/ml may inhibit the L-type calcium channels of ventricular myocytes, and depress the opening of calcium channel.