Effects of serum containing dioscin on sodium channel in ventricular myocytes of rats / 中草药

ABSTRACT

Objective: To investigate the effects of serum containing dioscin on sodium current (INa) and reveal the mechanisms of cardioprotection and antiarrhymias. Methods: Serum was obtained from the aortaventralis from Wistar rats after ig administration 4 d of dioscin 300 mg/kg, twice daily for 4 d. Single ventricular myocytes were isolated from adult rat hearts by enzymatic dissociation and the effects of dioscin on INa were observed by whole-cell patch clamp. Results: Serum containing dioscin shifted downward the I-V curve with increased peak current density. With the effects of 1, 10, and 100 μL serum containing dioscin, the peak current density was dose-dependently changed from (-52.10 ± 3.80) pA/pF to (-76.44 ± 4.09) pA/pF and (-81.96 ± 4.70) pA/pF, respectively (P < 0.01 vs control); Dioscin facilitated the activation process with the inactivation process unchanged. The half activation potential was changed from (-57.69 ± 1.86) mV to (-59.71 ± 2.57) mV, ( -66.56 ± 1.32) mV (P < 0.01 vs control), and (-68.52 ± 3.91) mV (P < 0.01 vs control), respectively; The recovery process of sodium channel was accelerated by 1, 10, and 100 μL serum containing dioscin with the recovery constant τ changed from (150.73 ± 21.49) ms to (143.19 ± 13.88) ms, (84.83 ± 18.03) ms (P < 0.01 vs control), and (80.63 ± 13.89) ms (P < 0.01 vs control). Conclusion: Serum containing dioscin could increase the sodium current by facilitating the activation process and accelerating the recovery process of sodium channel.