平衡冷冻后红细胞胞内未冻水的状态

The States of Unfrozen Water in Erythrocytes After Equilibrium Freezing

基于Boyle Van tHoff关系设计了 2种独立的实验方案 ,研究了红细胞内束缚水的状态 .第一种方案使用电子粒子计数仪 (EPC)测定了室温下在不同浓度的NaCl溶液中取得渗透平衡的红细胞的体积 (V) ,其中包括红细胞的等渗体积V0 (与 0 .9%的NaCl溶液取得渗透平衡的红细胞体积 ) .第二种方案使用差示扫描量热仪(DSC)测定了不同压积比的红细胞悬液慢速冷冻的放热量 .通过理论模型计算 ,进一步得到红细胞的最终平衡体积 (Vf) .平衡冷冻的最终体积与细胞内非渗透性体积(Vb)存在差别 ,这一差别被认为是细胞内束缚水的体积 .实验结果表明 :(1)两种实验方法等效 ;(2 )平衡冷冻后胞内几乎没有自由水 ,亦即红细胞内束缚水只有一种状态 ,为结合水 .

Two independent experimental approaches are coupled to check the state of unfrozen water within RBCs. One is to an use electronic particle counter (EPC) (Multisizer TM 3, Beckman Coulter Inc., USA) at ambient temperature to measure the final osmotic equilibrium volume (V f) of RBCs exposed to solutions of different concentrations, and the other is to use differential scanning calorimeter (DSC) at subzero temperature to get the final stable cell volume (V f) by slowly freezing samples of different hemocrits. The isotonic volume, V 0, is obtained under the isotonic condition by EPC. The difference between the equilibrium volume after freezing and the osmotic inactive volume (V f-V b) is taken as the volume of bulk water left in cells. The results of the experiments show that (1) the two methods are equivalent, and (2) there is nearly no bulk water left in cells after equilibrium freezing, that is, the unfrozen water in RBCs after equilibrium freezing exists in only one state, i.e., bound water.