Effect of paraquat and metoxychlor on antioxidant enzymes in frog Rana esculenta L. liver

Abstract

We examined the influence of a sublethal dose of paraquat and metoxychlor on the activity of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase in the liver of the edible frog Rana esculenta. The experiments have shown that after 6 days of injections with paraquat or metoxychlor, the enzyme that decomposes reactive oxygen species is glutathione peroxidase, whereas after 12 days of the treatment with the pesticides, the enzyme responsible for detoxification of hydrogen peroxide is catalase. Superoxide dismutase activity in the liver after the paraquat or metoxychlor treatment, both for 6 and 12 days, seems to be sufficient to protect the liver against the superoxide anion, which can be produced during the microsomal biotransformation of pesticides.