兔晶状体电位差的电生性成分。

An electrogenic component of the potential difference in the rabbit lens.

作者信息

Paterson C A, Neville M C, Jenkins R M, Cullen J P

出版信息

Biochim Biophys Acta. 1975 Jan 28;375(2):309-16. doi: 10.1016/0005-2736(75)90198-4.

Abstract

The normal resting potential of the rabbit lens, -70mV, is altered to -59mV by ouabain concentrations up to 5-1- minus 6M, and to -52mV at 4 degrees C. Ouabain acts only at the anterior lens surface. The temperature effect id completely reversible. The Hodgkin-Katz-Goldman equation can be used with the measured lens potentials and Na+ and K+ levels in the lens and bathing medium to obtain alpha, the ration of the membrane permeabilities to Na+ and K+. The alpha-values obtained were 0.052 at 4 degrees C and 0.053 in 5-10 minus 6M ouabain. These data suggest that the change in potential due to cold and ouabain is caused by an inhibition of an electrogenic Na+ ump in the anterior lens epithelium.

摘要

兔晶状体的正常静息电位为-70mV，在高达5×10⁻⁶M的哇巴因浓度下，该电位改变为-59mV，在4℃时变为-52mV。哇巴因仅作用于晶状体前表面。温度效应是完全可逆的。利用测得的晶状体电位以及晶状体和浸泡介质中的Na⁺和K⁺水平，可将霍奇金-卡茨-戈德曼方程用于计算α，即膜对Na⁺和K⁺的通透性之比。在4℃时获得的α值为0.052，在5×10⁻⁶M哇巴因中为0.053。这些数据表明，寒冷和哇巴因引起的电位变化是由前晶状体上皮中一种电生Na⁺泵的抑制所导致的。