Kamada T, McMillan D E, Yamashita T, Otsuji S
Department of Laboratory Medicine, Faculty of Medicine, Kagoshima University, Japan.
Diabetes Res Clin Pract. 1992 Apr;16(1):1-6. doi: 10.1016/0168-8227(92)90128-e.
In vivo age-related changes in membrane fluidity of erythrocytes were investigated by a spin label method after fractionation of the cells by discontinuous density gradient centrifugation. Membrane fluidity was lower in older than in younger erythrocytes in both the normal and diabetic subjects. Cells from diabetic subjects showed a significantly lower level of membrane fluidity for all three age groups (younger, middle and older) than the corresponding cells from normal subjects. The magnitude of progression in the decrease in membrane fluidity in erythrocytes did not differ significantly between both groups of subjects. Both erythrocyte ATP and acetylcholinesterase activity declined, while glycosylated hemoglobin (HbA1c) increased with cell age in both groups of subjects. The HbA1c level in each corresponding fraction was higher in diabetic subjects than normal subjects, but was not correlated with membrane fluidity in either group. Neither the ATP level nor acetylcholinesterase activity in each corresponding fraction differed between groups. Membrane fluidity was significantly correlated with acetylcholinesterase activity in both normal and diabetic subjects. Our results indicate that decreased erythrocyte membrane fluidity in diabetic patients does not form gradually during their life span but develops soon after the cells enter the circulation or during their maturation in the bone marrow.
通过自旋标记法，在采用不连续密度梯度离心法对细胞进行分级分离后，研究了红细胞膜流动性的体内年龄相关变化。在正常和糖尿病受试者中，老年红细胞的膜流动性均低于年轻红细胞。糖尿病受试者的细胞在所有三个年龄组（年轻、中年和老年）中的膜流动性水平均显著低于正常受试者相应的细胞。两组受试者红细胞膜流动性下降的进展幅度无显著差异。两组受试者中，红细胞ATP和乙酰胆碱酯酶活性均随细胞年龄下降，而糖化血红蛋白（HbA1c）则随细胞年龄增加。糖尿病受试者各相应分级中的HbA1c水平高于正常受试者，但两组中均与膜流动性无关。两组之间各相应分级中的ATP水平和乙酰胆碱酯酶活性均无差异。在正常和糖尿病受试者中，膜流动性均与乙酰胆碱酯酶活性显著相关。我们的结果表明，糖尿病患者红细胞膜流动性降低并非在其寿命期间逐渐形成，而是在细胞进入循环后不久或在骨髓中成熟期间就已发生。
