在红细胞低温保存或冻干保存中,高浓度保护剂的添加和洗涤会使细胞体积收缩或膨胀,造成溶血损失,但其体积并非单调收缩或膨胀到最后平衡体积,而是要经历更严重的体积变化后再趋于平衡。本研究以NaCl溶液来模拟保护剂的添加与洗涤过程.将38种不同浓度的NaC;溶液,以一步直接法、4步等体积法或4步等摩尔浓度变化法添加到红细胞中,测定其溶血率。若以溶血率10%为标准,红细胞所能承受的最小渗透压在161mOsmol/k附近,而最大渗透压与溶液添加方式有关,等体积添加法效果较好(其值约为5680mOsmol/kg)。研究中还将12%、18%NaCl溶液以4步等体积法加到红细胞中,再用生理盐水以三种方式洗涤,发现等摩尔浓度变化法洗涤效果最好;洗涤后溶血率大大增加,说明很多细胞虽然在保护剂添加时未溶血,但膜脆性已改变,难以恢复到等渗时体积。
The addition and removal of the protective agents will cause some hemolysis of red blood cells (RBCs) when lyophilized or cryopreserved. During the addition and removal, instead of shrinking or swelling to the last equilibrium volume monotonously, the cells suffer a more serious volume excursion and then reach the equilibrium volume. In this paper, the addition and washing of NaCl solutions were used to simulate the addition and removal of protective agents. 38 NaCl solutions of different osmolalities were added to RBCs with different methods, and then the hemolysis rates were measured. If 10% hemolysis is used as the criterion, the minimum osmolality that RBCs can tolerate is about 161mOsmol/kg. But the maximum osmolality is related to the addition method. The 4-step fixedvolume-method is the best (the maximum osmolality is about 5680mOsmol/kg). We also assessed the hemolysis rates after the removal of 12 % and 18 % NaCl solutions from RBCs. The best washing result was obtained when using the 4-step fixed-molarity-method, however the hemolysis rates rised remarkably after removal. This implied that the brittleness of the cell membrane had been changed and the cells couldn't restore to the original volume.