Alshuaib Waleed B, Mathew Mini V
Department of Physiology, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait.
J Membr Biol. 2006 Apr;210(3):193-8. doi: 10.1007/s00232-006-0001-x. Epub 2006 Aug 14.
We investigated the effects of vitamins C and E on the delayed-rectifier potassium current (IK(DR)), which is important in repolarizing the membrane potential, and on the transient A-type potassium current (IK(A)), which regulates neuronal firing frequency. The whole-cell patch-clamp technique was used to measure the currents from cultured Drosophila neurons derived from embryonic neuroblasts. The membrane potential was stepped to different voltages between -40 and +60 mV from a holding potential of -80 mV. IK(DR) and IK(A) measured in the vitamin C-containing solution (IK(DR) 305 +/- 16 pA, IK(A) 11 +/- 2 pA) were smaller than those measured in the control solution (488 +/- 21 pA, IK(A )28 +/- 3 pA). By contrast, IK(DR) and IK(A) measured in the vitamin E-containing solution (IK(DR) 561 +/- 21 pA, IK(A )31 +/- 3 pA) were greater than those measured in the control solution (422 +/- 15 pA, 17 +/- 2 pA). These results indicate that vitamins C and E can modulate potassium current amplitudes and possibly lead to altered neuronal excitability.
我们研究了维生素C和维生素E对延迟整流钾电流（IK(DR)）和瞬时A型钾电流（IK(A)）的影响，其中IK(DR)在膜电位复极化过程中起重要作用，IK(A)则调节神经元放电频率。采用全细胞膜片钳技术测量源自胚胎神经母细胞的培养果蝇神经元的电流。膜电位从-80 mV的钳制电位跃升至-40至+60 mV之间的不同电压。在含维生素C的溶液中测得的IK(DR)和IK(A)（IK(DR)为305±16 pA，IK(A)为11±2 pA）小于在对照溶液中测得的值（分别为488±21 pA和28±3 pA）。相比之下，在含维生素E的溶液中测得的IK(DR)和IK(A)（IK(DR)为561±21 pA，IK(A)为31±3 pA）大于在对照溶液中测得的值（分别为422±15 pA和17±2 pA）。这些结果表明，维生素C和维生素E可调节钾电流幅度，并可能导致神经元兴奋性改变。
