Mackie L H, Hochmuth R M
Department of Biomedical Engineering, Duke University, Durham, NC.
Blood. 1990 Sep 15;76(6):1256-61.
With the use of micromanipulation techniques, the shear modulus or "rigidity" mu, the recovery time tc, and the unfolding time tf for individual sickle cells have been measured at different oxygen tensions, temperatures, and cell densities. In these experiments, the partial pressure of oxygen was varied from 156 to 40 mm Hg and the temperature was controlled at 25 degrees C or 37 degrees C. Three mean cellular hemoglobin concentrations were studied: 29 g/dL, 33 g/dL, and 46 g/dL. The lighter cells (29 and 33 g/dL) exhibited at most a threefold increase in rigidity as the pO2 was decreased from 156 to 40 mm Hg. At 25 degrees C, the densest cells (46 g/dL) also exhibited a threefold increase. However, at 37 degrees C, the rigidity of these cells increased eightfold between 156 to 40 mm Hg. Compared with normal cells, this gives a rigidity that is 18 times larger. In contrast to the values for mu, the values for tc and tf remained essentially unchanged (within the accuracy of the experiments) for the lighter cells and could not be measured for the densest cells.
利用显微操作技术,已在不同的氧张力、温度和细胞密度条件下,对单个镰状细胞的剪切模量或“刚性”μ、恢复时间tc和展开时间tf进行了测量。在这些实验中,氧分压在156至40毫米汞柱之间变化,温度控制在25℃或37℃。研究了三种平均细胞血红蛋白浓度:29克/分升、33克/分升和46克/分升。随着氧分压从156毫米汞柱降至40毫米汞柱,较轻的细胞(29和33克/分升)的刚性最多增加了三倍。在25℃时,密度最大的细胞(46克/分升)也增加了三倍。然而,在37℃时,这些细胞的刚性在156至40毫米汞柱之间增加了八倍。与正常细胞相比,这使得刚性增大了18倍。与μ的值不同,较轻细胞的tc和tf值基本保持不变(在实验精度范围内),而密度最大的细胞则无法测量。