Alterations in xenobiotic metabolizing enzymes in brain and liver of rats coexposed to endosulfan and malathion

✍ Scribed by Nadadur S. Srikanth; Prahlad K. Seth

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 427 KB
• Volume: 10
• Category: Article
• ISSN: 0260-437X
• DOI: 10.1002/jat.2550100303

✦ Synopsis

The effects of endosulfan (3 mg kg-' body wt., i.p.) and malathion (30 mg kg-* body wt.) and their coexposure on rat hepatic and brain xenobiotic metabolizing enzymes were investigated. Endosulfan was found to induce aminopyrine-mdemethylase (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-Stransferase (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-Stransferase 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.

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MATERIALS AND METHODS

Chemicals

Endosulfan (reference standard) and malathion (98% pure), obtained from the US Environmental Protection Agency and American Cyanamide? respectively, are used in the present study. All other chemicals used were of analytical grade.

Animals

Male Wistar albino rats of 150-200 g weight, obtained from an ITRC animal house colony and maintained under standard laboratory conditions, were used in the