Alterations in xenobiotic metabolizing enzymes in brain and liver of rats coexposed to endosulfan and malathion.
The effects of endosulfan (3 mg kg-1 body wt., i.p.) and malathion (30 mg kg-1 body wt.) and their coexposure on rat hepatic and brain xenobiotic metabolizing enzymes were investigated. Endosulfan was found to induce aminopyrine-n-demethylase (81%) and aniline hydroxylase (59%) activities significantly in liver and to a lesser extent in brain. Malathion treatment induced malathion carboxylesterase activity in both liver (50%) and brain (22%), significantly depleted liver glutathione (35%) content with stimulation of glutathione-S-transferase (50%) and inhibited the activity of mixed-function oxidases. In the coexposed animals, malathion's inhibitory influence on mixed-function oxidases and endosulfan's inhibitory effect on malathion carboxylesterase were found to dominate, while endosulfan potentiated the activity of glutathione-S-transferase significantly in liver (69%) and brain. A similar trend of alteration in coexposed brain was found, but to a lesser extent. A significant inhibition in brain acetylcholine esterase activity (42%) in the coexposed animals suggests that endosulfan may potentiate the toxicity of malathion by interfering with glutathione and carboxylesterase routes of malathion detoxification.
Srikanth
N S
NS
Developmental Toxicology Division, Industrial Toxicology Research Centre, Lucknow, India.
Seth
P K
PK
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D004726:Endosulfan / Q000633:toxicity*; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008294:Malathion / Q000633:toxicity*; D008297:Male; D006899:Mixed Function Oxygenases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D015262:Xenobiotics / Q000378:metabolism*
D015262:Xenobiotics; D006899:Mixed Function Oxygenases; D004726:Endosulfan; D008294:Malathion