Iliev I G
Central Laboratory of Biophysics, Bulgarian Academy of Sciences, Sofia.
Acta Physiol Pharmacol Bulg. 1989;15(4):59-69.
We have studied the behaviour of single sodium channels in cell-attached patches in neuroblastoma cell line N1E 115 at 8-15 degrees C modified by chloramine-T (CT). Application of the agent to the external surface of the membrane cause different effects: CT binds to the membrane and cause irreversible effects leading to a decrease of open channel lifetime at 10 or 20 mV relative potentials without affecting the amplitude of single channel current. Channels modified by CT show a tendency to occur in burst (they can open and close several times during depolarization). Therefore, the slower decay of the average current must be explained by the flickering behaviour of the modified channels. We also examined the effect of CT on the relationship between open time of the channels and membrane potential. On the other hand, a small decrease in the mean delay time as a function of membrane voltages was observed which probably is related to the three state model of inactivation. Our results suggest that CT modifies sodium channel inactivation.
我们研究了在8 - 15摄氏度下，氯胺 - T（CT）对神经母细胞瘤细胞系N1E 115中细胞贴附膜片上单钠通道行为的影响。将该试剂应用于膜的外表面会产生不同的效应：CT与膜结合并导致不可逆效应，在相对电位为10或20毫伏时导致开放通道寿命缩短，而不影响单通道电流的幅度。被CT修饰的通道有突发出现的趋势（它们在去极化过程中可以多次打开和关闭）。因此，平均电流较慢的衰减必须由修饰通道的闪烁行为来解释。我们还研究了CT对通道开放时间与膜电位之间关系的影响。另一方面，观察到平均延迟时间随膜电压有小幅下降，这可能与失活的三态模型有关。我们的结果表明CT改变了钠通道的失活。
