Adams S P, Notides A C
Department of Biophysics, University of Rochester, School of Medicine and Dentistry, New York 14642.
Fundam Appl Toxicol. 1987 Nov;9(4):715-21. doi: 10.1016/0272-0590(87)90178-3.
Hamster renal cortical slices bioactivated the synthetic estrogen, diethylstilbestrol (DES), to reactive metabolites that bound irreversibly to cellular proteins. Incubation of the slices for 30 min at 37 degrees C with 5 mM diethyl maleate prior to the addition of 50 nM [3H]DES for 60 min increased the nonextractable binding of [3H]DES metabolites to cellular protein by 150%, whereas addition of 5 mM glutathione (GSH) decreased the irreversible binding of [3H]DES by 17%. The addition of the 5 mM GSH to the incubation medium caused a 24% increase in tissue nonprotein sulfhydryl (NP-SH) content as estimated by reaction with Ellman's reagent after 30 min at 37 degrees C, while the addition of diethyl maleate for the same time period depleted tissue NP-SH levels by 54%. Kidneys from hamsters treated with the GSH synthesis inhibitor L-buthionine-(S,R)-sulfoximine at a dosage of 1 mmol/kg body wt for 2 hr had 45% of the NP-SH content as compared with kidneys of saline-treated controls. The irreversible binding of [3H]DES metabolites was increased by 60% in renal cortical slices from L-buthionine sulfoximine-treated hamsters. Non-extractable binding of [3H]DES metabolites to renal DNA was not observed. These results suggest that GSH, the predominate NP-SH in the cell, protects against the irreversible binding of DES metabolites to cellular macromolecules.
仓鼠肾皮质切片可将合成雌激素己烯雌酚（DES）生物活化为与细胞蛋白质不可逆结合的反应性代谢产物。在加入50 nM [³H]DES孵育60分钟之前，将切片在37℃下与5 mM马来酸二乙酯孵育30分钟，可使[³H]DES代谢产物与细胞蛋白质的不可提取结合增加150%，而加入5 mM谷胱甘肽（GSH）可使[³H]DES的不可逆结合减少17%。在37℃下孵育30分钟后，通过与埃尔曼试剂反应估计，向孵育培养基中加入5 mM GSH可使组织非蛋白巯基（NP-SH）含量增加24%，而在相同时间段内加入马来酸二乙酯可使组织NP-SH水平降低54%。用1 mmol/kg体重的GSH合成抑制剂L-丁硫氨酸-（S，R）-亚砜亚胺处理仓鼠2小时，其肾脏的NP-SH含量是生理盐水处理对照组肾脏的45%。在L-丁硫氨酸亚砜亚胺处理的仓鼠的肾皮质切片中，[³H]DES代谢产物的不可逆结合增加了60%。未观察到[³H]DES代谢产物与肾脏DNA的不可提取结合。这些结果表明，细胞中主要的NP-SH即GSH可防止DES代谢产物与细胞大分子的不可逆结合。
