Schmidt W, Böning D, Braumann K M
Respir Physiol. 1987 May;68(2):215-25. doi: 10.1016/s0034-5687(87)80007-5.
Hemoglobin-oxygen-binding characteristics and essential influencing factors were investigated in human erythrocytes of different age separated by density gradient centrifugation. The most important age-dependent changes of the cell milieu are losses of K+, organic phosphates and water; the latter also leads to an increased concentration of negative charges on Hb. This augments the Donnan effect, which is only partly compensated for by a decrease of DPG-. The oxygen dissociation curve of the oldest fraction (P50 23.4 mm Hg) is shifted to the left compared to young cells (P50 29.2 mm Hg), and Hills 'n' is decreased (old cells 2.31, young cells 2.74). The Bohr effect for CO2 increases in the old population (BCCO2 at 50% SO2 -0.63 and -0.24 for old and young erythrocytes, respectively). This effect is less pronounced for the Bohr coefficients for lactic acid (delta BCLac 0.09). Most cell age-dependent alterations of Hb-O2-binding (including BCCO2) are explainable by opposite alterations of [Hb] and [DPG], causing the change of the ratio [DPG]/[Hb] from 1.3 to 0.7 during the aging process of the erythrocytes. Minor effects may result from aging of the Hb-molecule itself.
通过密度梯度离心法分离不同年龄的人红细胞，研究其血红蛋白与氧结合的特性及主要影响因素。细胞内环境随年龄变化的最重要改变是钾离子、有机磷酸盐和水分的流失；水分流失还会导致血红蛋白上负电荷浓度增加。这增强了唐南效应，而二磷酸甘油酸（DPG）-的减少只能部分补偿该效应。最老部分红细胞（P50为23.4毫米汞柱）的氧解离曲线相对于年轻细胞（P50为29.2毫米汞柱）向左移动，且希尔系数“ n”降低（老细胞为2.31，年轻细胞为2.74）。老年人群中二氧化碳的玻尔效应增强（在50%血氧饱和度时，老年和年轻红细胞的BCCO2分别为-0.63和-0.24）。乳酸的玻尔系数变化（δBCLac为0.09）时，这种效应不太明显。血红蛋白与氧结合的大多数随细胞年龄变化的改变（包括BCCO2）可以用血红蛋白浓度（[Hb]）和二磷酸甘油酸浓度（[DPG]）的相反变化来解释，在红细胞衰老过程中，[DPG]/[Hb]的比值从1.3变为0.7。血红蛋白分子本身的衰老可能产生较小影响。
