Oxidative stress in tumour-bearing fore-stomach and distant normal organs of Swiss albino mice

Abstract

<span style="mso-bidi-language:HI">Antioxidant status in the tumour-bearing fore-stomach and distant normal organs (liver, spleen, kidney and heart) was investigated in Swiss albino mice. In addition, the cytochrome P₄₅₀ (cyt P₄₅₀) system was also examined in the liver. Benzo(a)pyrene [B(a)p] (8 doses of 1 <span style="mso-bidi-font-family:Arial;mso-bidi-language:HI">mg/0.l<i> </i><span style="mso-bidi-language:HI">ml) was administered twice a week for 4 weeks to develop fore-stomach tumour. The animals were sacrificed at the end of 140 days. The specific activities of catalase (CAT), DT-diaphorase (DTD) and glutathione-S-transferase (GST) were found decreased, and the level of reduced glutathione (GSH) and the specific activity of lactate dehydrogenase (LDH) increased in the tumour-bearing fore-stomach; however, no change was observed in superoxide dismutase (SOD) activity. The specific activities of antioxidant enzymes, and levels of GSH were also altered in the normal organs, depending upon the type of tissue. In addition, the contents of cyt P₄₅₀ and cyt b₅. and the activity of NADPH cyt P₄₅₀ reductase were significantly decreased in the fiver. The results suggest increased oxidative stress in the tumour, and disturbance in the cooperative antioxidant functions in the distant normal organs. Inhibition of cyt P₄₅₀ system reflected the possible adverse effect on drug metabolism function of the liver. Since, the antioxidant potential and the drug metabolism function were altered, the findings may have relevance to the radiation and chemotherapy of cancer.

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