Are Changes of the Cell Membrane Structure Causally Involved in the Aging Process?
Are Changes of the Cell Membrane Structure Causally Involved in the Aging Process?
复制标题
细胞膜结构的变化是否与衰老过程有关？
DOI：
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复制
发表时间：
2002
影响因子：
5.2
通讯作者：
G. Spiteller
中科院分区：
文献类型：
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作者：
G. Spiteller
脂质过氧化是通过增殖、损伤和衰老来识别的。这些不同事件之间的联系是细胞壁结构的变化，它激活了膜结合的磷脂酶。这些裂解磷脂。因此，释放的多不饱和脂肪酸(PUFAs)是脂肪氧合酶的底物，它同样能接受亚油酸和花生四烯酸，并产生脂质过氧化氢(LOOHs)。如果游离多不饱和脂肪酸的数量超过一定数量，脂肪氧合酶就会自杀。其结果是释放了自由铁离子，这些离子通过形成自由基与LOHs反应。这些都会引发连锁反应。在这个过程中产生的LOO·自由基通过环氧化作用攻击蛋白质、核酸和所有不饱和化合物的双键。此外，LOHs还会被分解成有毒的环氧酸和αβγδ不饱和醛。这两个物种都与谷胱甘肽发生反应。由此产生的产物似乎可以诱导细胞凋亡。由于创伤或老化产生的产物是由LOOHs分解形成的，因此研究由纯PUFA产生的人工生成的脂质过氧化产物的生理作用可以简化老化过程的研究。含脂肪多不饱和脂肪酸的热分解产生了LOOHs的降解产物。这些产品通过在肠道中的吸附而被诱导进入体内。它们至少部分结合在低密度脂蛋白(LDL)中。初步研究似乎表明，过量摄入富含多不饱和脂肪酸的饮食只会在两天后导致氧化型低密度脂蛋白/多不饱和脂肪酸的增加，年轻人增加一倍以上，老年人增加两倍以上。
Lipid peroxidation is recognized by proliferation, wounding, and aging. The connecting link between these different events is a change in cell wall structure, which activates membrane bound phospholipases. These cleave phospholipids. Thus liberated polyunsaturated fatty acids (PUFAs) are substrates for lipoxygenases, which accept equally well linoleic acid and arachidonic acid and generate lipid hydroperoxides (LOOHs). If the amount of free PUFAs exceeds a certain amount, lipoxygenases commit suicide. The consequence is liberation of free iron ions that react with LOOHs by formation of radicals. These start a chain reaction. LOO• radicals produced in the course of this process attack proteins, nucleic acids, and also double bonds of all unsaturated compounds by epoxidation. Morever LOOHs are decomposed to toxic epoxy acids and αβγδ‐unsaturated aldehydes. Both species react with glutathione. The resulting products seem to induce apoptosis. Since the products generated by wounding or aging are formed by decomposition of LOOHs the investigation of the aging processes can be simplified by studying the physiological action of artificially generated lipid peroxidation products derived from pure PUFAs. Degradation products of LOOHs are generated by thermal decompositon of fat‐containing PUFAs. These products are induced into the body by adsorption in the intestine. They are at least partly incorporated in low density lipoproteins (LDLs). Primarily investigations seem to indicate that an overload of a diet rich in PUFAs induces only after two days an increase in oxidized LDL/PUFAs for a factor up to two in young people and for a factor of more than two in old individuals.
影响因子：
15.9
作者：
BERLINER, JA;TERRITO, MC;FOGELMAN, AM
通讯作者：
FOGELMAN, AM