Kadlubowski M, Agutter P S
Br J Haematol. 1977 Sep;37(1):111-25.
Human erythrocytes from healthy male donors were fractionated with respect to in vivo age by simple centrifugation in order to characterize changes in the functional integrity of the membrane during the life-span of the cell. The three enzymes, Na/K-ATPase, glyceraldehyde-3-phosphate dehydrogenase and NADH-ferricyanide reductase, were found not to change with age, but significant age-dependent decreases were observed in the cases of acetylcholinesterase, phosphoglycerate kinase, purine nucleoside phosphorylase, adenylate kinase, Mg-ATPase and alkaline phosphatase. The possibility that these changes were attributable to mechanisms other than age-related inactivation, such as reticulocyte contamination, differential resealing and crypticity, was investigated. Only the decrease in acetylcholinesterase could be explained wholly in terms of reticulocyte contamination. A decrease in membrane integrity on ageing was observed, which accounted for approximately half the change in alkaline phosphatase and may have contributed to the other enzyme activity changes. This membrane integrity effect masked a real decrease in the highly cryptic NADH-ferricyanide reductase, this decrease being apparent only after total disaggregation of the membrane with nonionic surfactant.
为了表征细胞寿命期间膜功能完整性的变化，通过简单离心对来自健康男性供体的人类红细胞按体内年龄进行了分级分离。发现钠钾ATP酶、甘油醛-3-磷酸脱氢酶和NADH-铁氰化物还原酶这三种酶不会随年龄变化，但在乙酰胆碱酯酶、磷酸甘油酸激酶、嘌呤核苷磷酸化酶、腺苷酸激酶、镁ATP酶和碱性磷酸酶的情况下，观察到明显的年龄依赖性下降。研究了这些变化可能归因于与年龄相关的失活以外的机制的可能性，如网织红细胞污染、差异重封和隐蔽性。只有乙酰胆碱酯酶的下降可以完全用网织红细胞污染来解释。观察到衰老过程中膜完整性下降，这约占碱性磷酸酶变化的一半，可能也导致了其他酶活性的变化。这种膜完整性效应掩盖了高度隐蔽的NADH-铁氰化物还原酶的实际下降，这种下降只有在用非离子表面活性剂使膜完全解体后才明显。
