SELENIUM AND GLUTATHIONE-PEROXIDASE IN SEMINAL PLASMA OF MEN AND BULLS
SELENIUM AND GLUTATHIONE-PEROXIDASE IN SEMINAL PLASMA OF MEN AND BULLS
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DOI：
10.1530/jrf.0.0830785
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发表时间：
1988-07-01
期刊：
影响因子：
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通讯作者：
VANHAPERTTULA, T
中科院分区：
文献类型：
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作者：
KANTOLA, M;SAARANEN, M;VANHAPERTTULA, T
牛精浆中硒和谷胱甘肽过氧化物酶（GSH-Px）含量高，人精浆中含量低。在男性精浆中，硒与凝胶过滤分离的两个大分子有关，但在相同的分数中未发现GSH-Px。公牛精浆中的硒与两种蛋白相关，可通过凝胶过滤和阴离子交换层析分离。两种大分子均具有GSH-Px活性，且在pH 7.0时具有相同的最优值。然而，他们对热处理的反应不同。公牛的精囊分泌液中含有这两种蛋白质，而在壶腹、前列腺和考伯腺的分离中也发现了较大的分子。较大的酶显然是较小的酶的四聚体。这两种酶对重金属和一些二价金属离子都极为敏感。谷胱甘肽引起激活，而其他还原剂则抑制。Triton X-100无抑制作用，脱氧胆酸钠有抑制作用。这些性质是磷脂过氧化氢GSH-Px的典型特征。由此可见，这种硒依赖酶可能在保护牛精子免受氧自由基损伤中起重要作用，而在人类中，这种机制不起作用。
High levels of selenium and glutathione peroxidase (GSH-Px) were found in bull seminal plasma but low concentrations in human seminal plasma. In man the seminal plasma selenium was associated with two macromolecules separable by gel filtration, but no GSH-Px was found in the same fractions. Selenium in bull seminal plasma was associated with two proteins, which could be separated by gel filtration and anion exchange chromatography. Both macromolecules coeluted with GSH-Px activity and had identical optima at pH 7.0. Their responses to thermal treatment, however, differed. Seminal vesicle secretory fluid in the bull contained both these proteins, while the larger molecule was also found in fractionations of ampulla, prostate and Cowper''s glands. The larger enzyme form is evidently a tetramer of the smaller one. Both enzyme forms were extremely sensitive to heavy metals and some divalent metal ions. GSH caused an activation while other reducing agents were suppressive. Triton X-100 had no effect, while sodium deoxycholate was inhibitory. These properties are typical for a phospholipid hydroperoxide GSH-Px. It is concluded that this selenium-dependent enzyme may be important in the protection of bovine spermatozoa against damage caused by oxygen radicals, while in man such a mechanism is not functional.