Quantitative significance of glutathione and glutathione-S-transferase in regulating benzo[a]pyrene anti diol-epoxide level in reconstituted C3H/10T1/2 cell lysates, and comparison to rat liver.
Quantitative significance of glutathione and glutathione-S-transferase in regulating benzo[a]pyrene anti diol-epoxide level in reconstituted C3H/10T1/2 cell lysates, and comparison to rat liver.
复制标题
谷胱甘肽和谷胱甘肽-S-转移酶在调节重构的 C3H/10T1/2 细胞裂解物中苯并[a]芘抗二醇环氧化物水平中的定量意义，并与大鼠肝脏进行比较。
DOI：
10.1093/carcin/5.2.143
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发表时间：
1984
期刊：
影响因子：
4.7
通讯作者：
Fahl,WE
中科院分区：
文献类型：
--
作者：
Ho,D;Fahl,WE
用[3H]苯并[a]芘（BP）和谷胱甘肽（GSH）或纯化的谷胱甘肽转移酶独立重组诱导的10T1/2细胞微粒体。在孵育提取物中测量了初级banti7,8 -二氢二醇9,10-环氧化物（r-7，t-8二羟基-t-9,10-氧-7,8,9,10四氢苯[a]芘）水解产物7,10/8,9-四醇的水平，使我们能够监测孵育过程中游离抗二醇环氧化物的水平，并确定GSH或GSH转移酶对其的独立影响。在测试的浓度范围内（0-4.0 mM）， GSH单独对抗二醇环氧化物水平没有影响，然而，从大鼠肝脏中添加纯化的GSH转移酶导致抗二醇环氧化物、9,10-环氧化物和7,8-环氧化物的剂量依赖性偶联，分别在0.036、0.039和0.17单位GSH转移酶/ml时发生50%的偶联。在10T1/2细胞中测定gsh转移酶浓度（0.15 ~ 0.27单位/ml细胞质液），重组后游离环氧抗二醇还原率为95%；这种gsh转移酶浓度仅占大鼠肝脏中gsh转移酶浓度的6%。结果表明，在10T1/2细胞和大鼠肝细胞中，GSH-转移酶催化的GSH偶联在确定细胞内抗二醇环氧化物水平方面具有定量意义。
Induced 10T1/2 cell microsomes were independently reconstituted with [3H]benzo[a]pyrene (BP) and glutathione (GSH) or purified GSH-transferases. Levels of the primary BPanti7,8-dihydrodiol 9,10-epoxide (r-7,t-8 dihydroxy-t-9,10-oxy-7,8,9,10 tetrahydrobenzo[a]pyrene) hydrolysis product, 7,10/8,9-tetrol, were measured in incubation extracts, enabling us to monitor the level of freeantidiol-epoxide in incubations and to determine the independent effects of GSH or GSH-transferases upon it. GSH alone had no effect onantidiol-epoxide levels over the concentration range tested (0–4.0 mM), however, the addition of purified GSH-transferase from rat liver resulted in a dose-dependent conjugation ofantidiol-epoxide as well as 9,10-epoxide and 7,8-epoxide with 50% conjugation occurring at 0.036, 0.039 and 0.17 units GSH-transferase/ml, respectively. Freeantidiol-epoxide was reduced by >95% when we reconstituted with the GSH-transferase concentration which we measured in 10T1/2 cells (0.15–0.27 units/ml cell cytosol); this GSH-transferase concentration represents only 6% of that found in rat liver. The results suggest that in both 10T1/2 cells and rat hepatocytes GSH-transferase catalyzed GSH conjugation is quantitatively significant in determining the intracellular level ofantidiol-epoxide.