Siddik Z H, Mimnaugh E G, Trush M A, Gram T E
Biochem J. 1980 Jun 15;188(3):889-93. doi: 10.1042/bj1880889.
Feeding male weanling rats on a vitamin A-deficient diet for 6 weeks resulted in significant increases (44-57%) in glutathione S-aryl-, S-aralkyl- S-alkyl- and S-epoxidetransferase activities in the liver cytosol. Only the S-aralkyl- (27%) and S-alkyltransferase (14%) activities were significantly increased in the kidney as a result of deficiency. There was no effect on any of the pulmonary glutathione S-transferase activities. The increases in hepatic transferase activities were due primarily to increases (25-96%) in the apparent Vmax. There were no changes in the apparant Km of any of the four drug substrates employed. With 3,4-dichloronitrobenzene as the second substrate, the apparent Km for glutathione was increased by over 2-fold in vitamin A-deficient livers as compared with controls. The relationship between these results and enhanced susceptibility to chemical carcinogens in vitamin A deficiency is briefly discussed, and comparison is made between the effects of this nutritional state and pretreatment with drug inducers on the glutathione S-transferases.
给雄性断奶大鼠喂食缺乏维生素A的饲料6周，导致肝细胞质中谷胱甘肽S-芳基、S-芳烷基、S-烷基和S-环氧化物转移酶活性显著增加（44%-57%）。由于缺乏维生素A，肾脏中只有S-芳烷基转移酶（27%）和S-烷基转移酶（14%）的活性显著增加。对任何肺谷胱甘肽S-转移酶活性均无影响。肝转移酶活性的增加主要是由于表观Vmax增加（25%-96%）。所使用的四种药物底物的表观Km均无变化。以3,4-二氯硝基苯作为第二种底物，与对照组相比，维生素A缺乏的肝脏中谷胱甘肽的表观Km增加了2倍以上。简要讨论了这些结果与维生素A缺乏时对化学致癌物易感性增加之间的关系，并比较了这种营养状态和药物诱导剂预处理对谷胱甘肽S-转移酶的影响。
