Ekeke G I, Ibeh G O
Department of Biochemistry, University of Port Harcourt, Nigeria.
Clin Chem. 1988 Jul;34(7):1443-6.
Neuraminic (sialic) acid concentrations in serum from normal and sickle cell (HbSS) subjects were determined for discrete age groups from childhood through adolescence. Values in sickle cell disease were consistently lower over the entire age range. We further investigated the effect of exogenous sialic acid on the rate of sickling reversion of HbSS erythrocytes and demonstrated that this compound in millimole per liter concentrations could revert pre-sickled erythrocytes to their normal morphology in a concentration-dependent manner. When subjected to partial de-sialation with sialidase (EC 3.2.1.18), the HbSS erythrocytes not only sickled faster upon deoxygenation, they also reverted more slowly on treatment with phenylalanine (a more efficient anti-sickling agent than sialic acid) than did untreated cells. We conclude that, in sickle cell disease, erythrocyte sialic acid content could play a significant role, not only in the control of the sickling rate in vivo, but also, after sickling has occurred, in the rate of recovery from a sickling crisis.
测定了从儿童期到青春期各离散年龄组正常人和镰状细胞病（HbSS）患者血清中的神经氨酸（唾液酸）浓度。在整个年龄范围内，镰状细胞病患者的值始终较低。我们进一步研究了外源性唾液酸对HbSS红细胞镰变逆转率的影响，结果表明，以毫摩尔每升浓度计的该化合物可使预镰变红细胞以浓度依赖的方式恢复其正常形态。当用唾液酸酶（EC 3.2.1.18）进行部分去唾液酸化处理时，HbSS红细胞不仅在脱氧时镰变更快，而且在用苯丙氨酸（一种比唾液酸更有效的抗镰变剂）处理后，其恢复正常形态的速度也比未处理的细胞慢。我们得出结论，在镰状细胞病中，红细胞唾液酸含量不仅在体内镰变率的控制中可能起重要作用，而且在镰变发生后，在镰变危机恢复的速率中也可能起重要作用。
