Morgenstern R, Guthenberg C, Mannervik B, DePierre J W, Ernster L
Cancer Res. 1982 Oct;42(10):4215-21.
We have examined the effects of adding glutathione and isolated cytosolic glutathione S-transferases A, B, and C to rat liver microsomes metabolizing benzo(a)pyrene. Addition of glutathione alone resulted in the conjugation of 15 to 20% of the total metabolites of benzo(a)pyrene, and this conjugation could be inhibited almost entirely by bromosulfophthalein (an inhibitor of glutathione S-transferases), indicating that it is catalyzed by the glutathione S-transferase present in microsomes. Addition of purified cytosolic glutathione S-transferases A, B, and C yielded about 30 to 40% conjugate formation. Analysis of metabolites by high-pressure liquid chromatography demonstrated that the formation of 4,5-diol of benzo(a)pyrene was decreased by at least 80% by conjugation and that the 7,8-diol was also decreased significantly (40 to 60%). In addition, it was found that glutathione S-transferase B is capable of conjugating benzo(a)pyrene 1,6- and 3,6-quinones.
我们研究了向代谢苯并(a)芘的大鼠肝微粒体中添加谷胱甘肽以及分离出的胞质谷胱甘肽S-转移酶A、B和C的效果。单独添加谷胱甘肽导致苯并(a)芘总代谢产物中有15%至20%发生结合，并且这种结合几乎可以被溴磺酞（谷胱甘肽S-转移酶的抑制剂）完全抑制，这表明它是由微粒体中存在的谷胱甘肽S-转移酶催化的。添加纯化的胞质谷胱甘肽S-转移酶A、B和C产生了约30%至40%的结合物形成。通过高压液相色谱对代谢产物进行分析表明，苯并(a)芘4,5-二醇的形成通过结合减少了至少80%，并且7,8-二醇也显著减少（40%至60%）。此外，还发现谷胱甘肽S-转移酶B能够使苯并(a)芘1,6-醌和3,6-醌发生结合。
