Akeo K, Hiramitsu T
Photon Medical Research Center, Hamamatsu University, School of Medicine, Shizuoka, Japan.
Pigment Cell Res. 1998 Oct;11(5):320-6. doi: 10.1111/j.1600-0749.1998.tb00742.x.
We previously observed the presence of autofluorescent lipofuscin or its like in retinal pigment epithelial (RPE) cells, which were incubated with linoleic acid hydroperoxides (LHP). We studied the effect of oxygen on the level of lipid peroxides in RPE cells in the presence of linoleic acids (LA) or LHP. The level of lipid peroxides in these cells was determined by use of the thiobarbituric acid-reactive substance (TBARS), which responded to oxygen concentrations qualitatively, and a linear regression analysis. Multiple linear regression analysis disclosed that treatment with LA for 24 hr resulted in detectable increase in the level of TBARS in the cells, whereas treatment with LA or LHP for 48 hr caused detectable decrease. Stepwise linear regression analysis showed that the level of TBARS decreased in an oxygen-tension dependent manner in the cells incubated with LA for 48 hr. Thus, it was shown that short-term incubation with LA increased the level of TBARS in the cells and that LA decreased its level in an oxygen-tension dependent manner. For these results, the postulation was made that the prolonged auto-oxidation of LA caused production of lipofuscin-like materials, a complex of lipid peroxides and proteins that were insoluble in SDS and acetic acid solution.
我们之前观察到，在用氢过氧化亚油酸（LHP）孵育的视网膜色素上皮（RPE）细胞中存在自发荧光脂褐素或类似物质。我们研究了在亚油酸（LA）或LHP存在的情况下，氧气对RPE细胞中脂质过氧化物水平的影响。通过使用硫代巴比妥酸反应性物质（TBARS）来测定这些细胞中脂质过氧化物的水平，TBARS对氧气浓度有定性反应，并进行线性回归分析。多元线性回归分析显示，用LA处理24小时导致细胞中TBARS水平有可检测到的增加，而用LA或LHP处理48小时则导致可检测到的降低。逐步线性回归分析表明，在用LA孵育48小时的细胞中，TBARS水平以氧张力依赖的方式降低。因此，结果表明，用LA短期孵育会增加细胞中TBARS的水平，而LA以氧张力依赖的方式降低其水平。基于这些结果，推测LA的长时间自动氧化导致了脂褐素样物质的产生，脂褐素样物质是脂质过氧化物和蛋白质的复合物，不溶于SDS和乙酸溶液。
