过氧化脂质、谷胱甘肽过氧化物酶和过氧化氢酶活性在实验性肝癌中变化规律的探讨

本文对实验性大鼠肝癌不同阶段血和组织中过氧化脂质(LPO)含量、谷胱甘肽过氧化物酶(GSH-Px)和过氧化氢酶(CAT)活性进行动态观察。LPO含量在肝癌形成前增高,以后随着肝癌的形成与生长逐渐降低。瘤组织中LPO含量显著低于癌旁组织和正常肝组织(P<0.01)。GSH-Px活性在诱癌6周后下降,CAT活性诱癌开始后即降低。癌组织中GSH-Px和CAT活性显著低于癌旁组织和正常肝组织(P<0.01)。提示诱癌过程中机体抗氧化系统严重受损;自由基、脂质过氧化损伤可能是肝癌发生的重要机理之一。

CHANGES IN LIPOPEROXIOE CONTENT. GLUTATHIONE PEROXIDASE AND CATALASE ACTIVITIES IN BLOOD AND LIVER TISSUES DURING HEPATOCARCINOGENESIS IN RATS.

Serial observations were performed on the content of lipoperoxide (LPO),activities of glutathione peroxidase (GSH-Px) and catalase (CAT) in blood liver tissues during hepatocarcinogenesis induced by diethylnitrosamine (DEN) in rats.The level of LPO in plasma and liver tissues of DEN-treated group remained high before the appearance of hepatoma and subsequently dropped to the normal level or even lower with the development and growth of hepatoma.All the neopiastic specimens had a significant lower value of LPO content than the normal tissues (P<0.01).The GSH-Px activity in erythrocyte and liver tissues of DEN-treated group.increased at the early stage and then markedly decreased.The activity of GAT in liver tissues of DEN-treated group markedly decreased even at the early stage of the experiment.At the end of this experiment,the activities of GSH-Px and CAT in liver tissues of DEN-treated group were only 22% and 24% of those of control,respectively.The activities of GSH-Px and CAT in tumor tissues were lower than those of the adjacent tumor-free and normal tissues (P<0.01,respectively).The results suggested that the antioxidant systec be severely impaired during hepatocarcinogenesis.The cell damage induced by active oxygen radical and lipid peroxide may be one of the mechanisms of chemical hepatocarcinogenesis.