<正>Objective:To study the effect of salvianolic acid A(SAA) on L-type calcium current(l-CaL) in isolated ventricular myocytes of Sprague-Dawley rats.Methods:SAA powder was dissolved in normal Tyrode’s solution to reach the concentrations of 1,10,100,and 1000μmol/L.The traditional whole-cell patch-clamp recording technique was employed to evaluate the effects of SAA on 1-CaL in single ventricular myocytes which were prepared by Langendorff perfusion apparatus from Sprague-Dawley rats.Results:SAA(1,10,100, and 1000μmol/L) inhibited l-CaL peak value by 16.23%±1.3%(n=6,P<0.05),22.9%±3.6%(n=6,P<0.05), 53.4%±3.0%(n=8,P<0.01),and 62.26%±2.9%(n=6,P<0.01),respectively.SAA reversibly inhibited l-CaL in a dose-dependent manner and with a half-blocking concentration(IC50) of 38.3μmol/L.SAA at 100μmol/L elevated theⅠ-Ⅴcurve obviously,and shifted the half-active voltage(V0.5) from(-15.78±0.86) mV to(-11.24±0.77) mV(n=6,P<0.05) and the slope(K) from 5.33±0.74 to 4.35±0.74(n=6,P>0.05).However,it did not alter the shapes ofⅠ-Ⅴcurve,steady-state inactivation curve,or recovery from inactivation curve.Conclusions: SAA inhibited l-CaL in a dose-dependent manner.It shifted the steady-state activation curve to a more positive voltage,which indicated that the drug affected the activated state of calcium channels,and suggested that the Ca2+ antagonistic effect of SAA be beneficial in the treatment of myocardial ischemia reperfusion injury.
Objective: To study the effect of salvianolic acid A (SAA) on L-type calcium current (I-CaL) in isolated ventdcular myocytes of Sprague-Dawley rats. Methods: SPA powder was dissolved in normal Tyrode's solution to reach the concentrations of 1, 10, 100, and 1000 μmol/L. The traditional whole-cell patch-clamp recording technique was employed to evaluate the effects of SAA on I-CaL in single ventricular myocytes which were prepared by Langendorff perfusion apparatus from Sprague-Dawley rats. Results: SPA (1, 10, 100, and 1000 μmol/L) inhibited I-CaL peak value by 16.23%± 1.3% (n=6, P〈0.05), 22.9% ± 3.6% (n=6, P〈0.05), 53.4% ± 3.0% (n=8, P〈0.01), and 62.26% ± 2.9% (n=8, P〈0.01), respectively. SAA reversibly inhibited I-CaL in a dose-dependent manner and with a half-blocking concentration (IC50) of 38.3 μmol/L. SAA at 100 μmol/L elevated the I-V curve obviously, and shifted the half-active voltage (V0.5) from (-15.78± 0.86) mV to (-11.24 ± 0.77) mV (n=6, P〈0.05) and the slope (K) from 5.33 ±0.74 to 4.35±0.74 (n=6, P〉0.05). However, it did not alter the shapes of I-V curve, steady-state inactivation curve, or recovery from inactivation curve. Conclusions: SAA inhibited I-CaL in a dose-dependent manner. It shifted the steady-state activation curve to a more positive voltage, which indicated that the drug affected the activated state of calcium channels, and suggested that the Ca2. antagonistic effect of SPA be beneficial in the treatment of myocardial ischemia reperfusion injury.