Department of Zoology, Laboratory of Gerontology, Bangalore University, Bangalore, 560 056, India.
Biogerontology. 2011 Aug;12(4):283-92. doi: 10.1007/s10522-011-9323-x. Epub 2011 Feb 26.
This study aims at determining the possible changes in intracellular calcium (Ca (i) (2+) ), plasma membrane calcium ATPase (PMCA) activity and phosphatidylserine (PS) along with glutathione (GSH) level in response to an oxidant challenge in vitro. Erythrocytes were isolated on Percoll and incubated with 2, 2'azobis (2-aminopropane) hydrochloride (AAPH) as well as with vitamin C preceding AAPH incubation. Membrane integrity in terms of hemolysis was negatively related to acetylcholine esterase (AChE) activity with the extent of reduction under OS being higher in the old erythrocyte than in the young. A divergent pattern was seen towards lower PMCA and higher (Ca (i) (2+) ) in the young and old cells. However, the PMCA activity in the stressed young cell was high when pre-treated with vitamin C. PS externalization in the young under OS is perhaps analogous to normal aging, with vitamin C preventing premature death. These findings suggest that young erythrocytes may benefit from vitamin C in therapies addressed towards the mechanisms underlying the reduced effects of OS.
本研究旨在确定细胞内钙（Ca(i)(2+)）、质膜钙 ATP 酶（PMCA）活性和磷脂酰丝氨酸（PS）以及谷胱甘肽（GSH）水平在体外氧化应激下可能发生的变化。红细胞用 Percoll 分离，用 2,2'偶氮双（2-氨基丙烷）盐酸盐（AAPH）孵育，并在 AAPH 孵育前用维生素 C 孵育。溶血方面的膜完整性与乙酰胆碱酯酶（AChE）活性呈负相关，氧化应激下的还原程度在老年红细胞中高于年轻红细胞。年轻和老年细胞中 PMCA 和（Ca(i)(2+)）均呈现出不同的模式，年轻细胞的 PMCA 活性更高，而老年细胞的（Ca(i)(2+)）更高。然而，在年轻细胞受到氧化应激之前用维生素 C 预处理，其 PMCA 活性很高。年轻红细胞在 OS 下的 PS 外排可能类似于正常衰老，维生素 C 可防止过早死亡。这些发现表明，年轻红细胞可能受益于维生素 C 治疗，针对 OS 减少的机制。
