细胞凋亡与谷胱甘肽－S－转移酶、谷胱甘肽－S－转移酶－π关系的研究

STUDY OF RELATIONSHIP BETWEEN APOPTOSIS AND GLUTATHIONE S-TRANSFERASE,GLUTATHIONE S-TRANSFERASE-π

经ＣＳＣ、ＤＥＮ、ＭＮＵ等致癌物转化和未转化的凋亡Ｒａｔ－１细胞谷胱甘肽－Ｓ－转移酶（ＧＳＴｓ）、谷胱甘肽－Ｓ－转移酶－π（ＧＳＴ－π）活性均较其相应的未凋亡细胞显著增高（Ｐ＜０．０５～０．０１）。经Ｎｏｒｔｈｅｒｎ杂交证实，上述凋亡细胞ＧＳＴ－πｍＲＮＡ表达水平也增高，这可能是导致ＧＳＴｓ和ＧＳＴ－π活性增高的主要原因。由于ＧＳＴｓ可催化谷胱甘肽（ＧＳＨ）与众多亲电子物质结合而有重要解毒功能，故推测培养细胞因营养匮乏引起凋亡时，其自身代谢产生的有毒物质无法及时被清除而积聚，可能启动了细胞自身的防御体系，行使自我保卫功能，从而刺激ＧＳＴｓ活性增高。

The present study has shown that S-Transferase(GSTs) and S-Transferase-π(GST-π) activity were elevated in the apoptotic control and transforming Rat-1 cells treated with CSC,DEN and MNU compared with non-apoptotic cells respectively( P<0.05～0.01) Furthermore , high expression of GST-π mRNA in apoptotic cells was also detected using Northern blot assay. It might be responsiblefor the high levels of GSTs and GST-π in apoptosis. As GSTs plays an important role in detoxication by catalyzing the conjugation of many eletrophilic compounds with reduced glutathione, we propose that apoptotic cultured cells caused by nutrition deficiency produce many toxic compounds through metabolism, the accumulated toxic compounds might initiate cellular self-defense system which stimultes the formation of GSTs.