Effect of chrysotile asbestos on cytochrome P-450-dependent monooxygenase and glutathione-S-transferase activities in rat lung.
The in vitro and in vivo effect of a carcinogenic variety of asbestos, chrysotile, both on xenobiotic metabolizing enzymes such as benzo[a]pyrene hydroxylase, epoxide hydrolase as well as glutathione-S-transferase activities and microsomal lipid peroxidation in rat lung were examined. The in vitro incubation of chrysotile with microsomes significantly adsorbed heme proteins, cytochrome P-450 and P-448 with the concomitant decrease in the dependent monooxygenase activities. The prolonged incubation of this mineral fibre with microsomes also resulted in the release of heme. It also led to the depletion in the activities of epoxide hydrolase and glutathione-S-transferase. However, it induced lipid peroxidation. When these in vitro effects were validated in vivo, the exposure to early stages produced similar alterations as observed in in vitro studies. However, reverse pattern in the alterations was observed after 90 days of exposure except in the case of lipid peroxidation which remained induced.
Rahman
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Q
Industrial Toxicology Research Centre, Lucknow, India.
Khan
S G
SG
Ali
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S
D000327:Adsorption; D000818:Animals; D001194:Asbestos / Q000494:pharmacology* / Q000633:toxicity; D017632:Asbestos, Serpentine; D001711:Biotransformation; D002273:Carcinogens; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D019388:Cytochrome P-450 CYP1A2; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D003580:Cytochromes / Q000378:metabolism; D004851:Epoxide Hydrolases / Q000378:metabolism; D005260:Female; D005982:Glutathione Transferase / Q000378:metabolism*; D006418:Heme / Q000378:metabolism; D066298:In Vitro Techniques; D015227:Lipid Peroxidation / Q000187:drug effects; D008168:Lung / Q000187:drug effects / Q000201:enzymology*; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology*; D010105:Oxygenases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D017632:Asbestos, Serpentine; D002273:Carcinogens; D003580:Cytochromes; D001194:Asbestos; D006418:Heme; D003577:Cytochrome P-450 Enzyme System; D010105:Oxygenases; C017170:Cyp1a2 protein, rat; D019388:Cytochrome P-450 CYP1A2; D005982:Glutathione Transferase; D004851:Epoxide Hydrolases