Laboratory of Gerontology, Department of Zoology, Bangalore University, Bangalore 560056, Karnataka, India.
Biogerontology. 2009 Dec;10(6):659-69. doi: 10.1007/s10522-009-9212-8.
The effects of oxidative stress (OS) on the rat erythrocytes (RBCs) that were fractionated on the percoll/BSA gradient into young and old cells were studied to find out if the altered Na+/H+ and Cl⁻/ HCO3⁻ antiporters and in turn the intracellular pH (pHi) could act as one of the promoters of cell death. Old cells were more spherical with lesser surface area, more fragile osmotically and had lesser protein sulphydryl content than the young cells. OS was induced in RBCs by 2,20-azobis (2-amidinopropane) dihydrochloride (AAPH). AAPH increased the superoxide dismutase (SOD) activity and MDA level and, the changes between the young and old. Interestingly, vitamin C was effective in reducing MDA in the old. Further, in the old a rapid Na+-dependent acidification in the presence of AAPH and a marginal acidosis in the presence of vitamin C were evident. Old RBCs exhibited higher acidosis and vitamin C was less effective in lowering the stress-induced acidosis compared to the young. Our studies suggest that increased acidosis followed by low intracellular pH could be one of the determinant factors for the disappearance of old RBCs from circulation, and perhaps of the young too under OS.
研究了在 Percoll/BSA 梯度上分离的年轻和衰老的大鼠红细胞（RBC）中氧化应激（OS）对红细胞的影响，以确定改变的 Na+/H+ 和 Cl⁻/HCO3⁻ 转运蛋白，以及随之而来的细胞内 pH（pHi）是否可以作为细胞死亡的促进剂之一。衰老的细胞比年轻的细胞更圆，表面积更小，对渗透压更脆弱，并且巯基蛋白含量更少。通过 2,20-偶氮双（2-脒基丙烷）二盐酸盐（AAPH）诱导 RBC 中的 OS。AAPH 增加了超氧化物歧化酶（SOD）活性和 MDA 水平，并且改变了年轻和衰老之间的关系。有趣的是，维生素 C 可有效降低衰老细胞中的 MDA。此外，在存在 AAPH 的情况下，衰老的 RBC 中会迅速发生依赖于 Na+的酸化，而在存在维生素 C 的情况下则会出现轻微的酸中毒。衰老的 RBC 表现出更高的酸中毒，并且与年轻的 RBC 相比，维生素 C 在降低应激诱导的酸中毒方面的效果较差。我们的研究表明，随后的酸中毒增加和低细胞内 pH 值可能是衰老的 RBC 从循环中消失的决定因素之一，在 OS 下，年轻的 RBC 也可能如此。
