effect of benzo [A] pyrene on glutathione s-transferase glutathione peroxidase the liver and kidney mouse mus musculus

ABSTRACT

The effect of benzo[a]pyrene [BaP] on the activities of glutathione S-transferase [GST] and glutathione peroxidase [GPx] and histology in the liver and kidney of the mouse, Mus musculus were investigated. Three treatment groups of mice [6 in each group] were injected with 200mg/kg BaP once a week. Groups 1,2 and 3 were sacrificed after two, four and eight weeks, respectively by cervical dislocation. Similarly three control groups of mice injected with corn-oil were sacrificed at week 2, week 4 and week 8. Sections of the liver and kidney of mice were stained with hematoxylin and eosin. The GST activity in the liver and kidney was significantly increased after two weeks compared to the control group [P<0.05]. The GPx activity in the liver significantly increased to a maximum at four weeks. After eight weeks, GST and GPx activities decreased in the treated mice liver compared to the control group. Grey-white hyperplastic nodules were visible in the liver after four weeks of treatment. The slides prepared from these tissues showed marked morphological changes where the hepatocytes were paler, more vacuolated and had lost their normal shape and arrangement. The kidney cells showed mild inflammation within the medulla and glomeruli after four weeks. After eight weeks severe inflammation was observed in medulla but there was no change in the other parts. In this study, it was found that differences in morphology and cellular changes in liver and kidney were time dependent. It is concluded that assay of GST activity provides a method to monitor antioxidant changes in mice liver and kidney after exposure to BaP. The result indicated that liver was main target for chemically induced toxicity