Vieira F L, Sha'afi R I, Solomon A K
J Gen Physiol. 1970 Apr;55(4):451-66. doi: 10.1085/jgp.55.4.451.
The apparent activation energy for the water diffusion permeability coefficient, P(d), across the red cell membrane has been found to be 4.9 +/- 0.3 kcal/mole in the dog and 6.0 +/- 0.2 kcal/mole in the human being over the temperature range, 7 degrees to 37 degrees C. The apparent activation energy for the hydraulic conductivity, L(p), in dog red cells has been found to be 3.7 +/- 0.4 kcal/mole and in human red cells, 3.3 +/- 0.4 kcal/mole over the same temperature range. The product of L(p) and the bulk viscosity of water, eta, was independent of temperature for both dog and man which indicates that the geometry of the red cell membrane is not temperature-sensitive over our experimental temperature range in either species. In the case of the dog, the apparent activation energy for diffusion is the same as that for self-diffusion of water, 4.6-4.8 kcal/mole, which indicates that the process of water diffusion across the dog red cell membrane is the same as that in free solution. The slightly, but significantly, higher activation energy for water diffusion in human red cells is consonant with water-membrane interaction in the narrower equivalent pores characteristic of these cells. The observation that the apparent activation energy for hydraulic conductivity is less than that for water diffusion across the red cell membrane is characteristic of viscous flow and suggests that the flow of water across the membranes of these red cells under an osmotic pressure gradient is a viscous process.
在7摄氏度至37摄氏度的温度范围内，已发现狗红细胞膜上水扩散渗透系数P(d)的表观活化能为4.9±0.3千卡/摩尔，人类红细胞的为6.0±0.2千卡/摩尔。已发现狗红细胞水力传导率L(p)的表观活化能在相同温度范围内为3.7±0.4千卡/摩尔，人类红细胞的为3.3±0.4千卡/摩尔。狗和人的L(p)与水的体相粘度η的乘积均与温度无关，这表明在我们的实验温度范围内，两种物种的红细胞膜几何形状对温度均不敏感。就狗而言，扩散的表观活化能与水的自扩散活化能相同，为4.6 - 4.8千卡/摩尔，这表明水在狗红细胞膜上的扩散过程与在自由溶液中的相同。人类红细胞中水扩散的活化能略高但显著，这与这些细胞较窄的等效孔中的水 - 膜相互作用一致。水力传导率的表观活化能低于水在红细胞膜上扩散的表观活化能这一观察结果是粘性流动的特征，表明在渗透压梯度下水在这些红细胞膜上的流动是一个粘性过程。
