title: Superoxide radical generation, NADPH oxidase activity, and cytochrome P-450 content of rat liver microsomal fractions in an experimental hyperthyroid state: relation to lipid peroxidation.
abstract: The effect of thyroid hormone treatment on hepatic microsomal functions related to NADPH-dependent electron transfer reactions was studied in rats given 0.1 mg T3/kg BW for 1, 2, 3, and 7 consecutive days. This treatment resulted in increased rates of O2-. generation by microsomal fractions, concomitantly with an enhancement in NADPH oxidase activity and decreased cytochrome P-450 content, in livers exhibiting increased respiration. Subsequent studies showed elevated levels of malondialdehyde in microsomal fractions and liver homogenates, as well as augmented chemiluminescent response in the latter system. These results indicate that the calorigenic effect of T3 on the liver tissue is accompanied by a stimulation of microsomal functions involving univalent reduction of oxygen. This cellular response might lead to a greater lipid peroxidative rate and cytochrome P-450 loss as secondary events of thyroid hormone action.
authors.forename: V
authors.initials: V
authors.lastname: Fernández
authors.forename: X
authors.initials: X
authors.lastname: Barrientos
authors.forename: K
authors.initials: K
authors.lastname: Kipreos
authors.forename: A
authors.initials: A
authors.lastname: Valenzuela
authors.forename: L A
authors.initials: LA
authors.lastname: Videla
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D006980:Hyperthyroidism / Q000378:metabolism*; D007700:Kinetics; D008054:Lipid Peroxides / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D019255:NADPH Oxidases; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013481:Superoxides / Q000378:metabolism*; D014284:Triiodothyronine / Q000097:blood / Q000494:pharmacology
chemical_list: D008054:Lipid Peroxides; D014284:Triiodothyronine; D013481:Superoxides; D008315:Malondialdehyde; D003577:Cytochrome P-450 Enzyme System; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases