论文部分内容阅读
目的:研究胡椒碱(PIP)对H2O2引起的单个兔心房肌细胞动作电位时程(APD)及L型钙电流(ICa,L)异常的保护作用。方法:采用全细胞膜片钳技术,观察10和50μmol/L的H2O2引起单个兔心房肌细胞APD及ICa,L的改变,以及预先应用7μmol/L的PIP对其的作用。结果:7μmol/L的PIP对正常兔心房肌细胞APD、ICa,L及L型钙通道动力学无明显影响。在10和50μmol/L的H2O2作用下,兔心房肌细胞APD50和APD90明显缩短(P<0.05),静息膜电位(RMP)绝对值显著下降(P<0.05),ICa,L峰值由(39.3±5.4)pA/pF降低至(32.8±2.0)pA/pF(P<0.05),电流-电压曲线上移,通道稳态激活曲线右移,通道稳态失活曲线左移,但恢复时间不变。预先给予7μmol/L的PIP可明显减轻H2 O2对APD、ICa,L的抑制作用(P<0.01),对L型钙通道动力学的异常影响。结论:PIP可减轻氧化应激对心房肌细胞APD、ICa,L的影响。
AIM: To investigate the protective effect of piperine on the abnormality of action potential time (APD) and L-type calcium current (ICa, L) induced by H2O2 in a single rabbit atrial myocytes. Methods: Whole-cell patch-clamp technique was used to observe the changes of APD, ICa, L in 10 and 50μmol / L H2O2 induced by a single rabbit atrial myocytes and the effect of 7μmol / L PIP. Results: 7μmol / L PIP had no significant effect on the APD, ICa, L and L-type calcium channels in normal rabbit atrial myocytes. The APD50 and APD90 of rabbit atrial myocytes were significantly decreased (P <0.05) and the absolute value of resting membrane potential (RMP) was significantly decreased (P <0.05) under the action of 10 and 50μmol / L H2O2. ± 5.4) pA / pF decreased to (32.8 ± 2.0) pA / pF (P <0.05). The current-voltage curve shifted upwards and the steady-state activation curve shifted to the right, while the steady-state inactivation curve shifted to the left. change. Pretreatment with PIP at 7μmol / L significantly reduced the abnormal effect of H2O2 on the dynamics of L-type calcium channel (P <0.01). Conclusion: PIP can reduce the effects of oxidative stress on APD, ICa, L in atrial myocytes.