Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.99.3 (diaphorase)
 5,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of thiamin deficiency on the metabolism of the oral contraceptive mestranol by female rat liver enzymes was determined. Rats were fed a diet for 3 weeks containing 0, .3, .7, 2.0, or 20 mcg thiamin/gm food before decapitation and extraction of liver microsomes. Mestranol was incubated with 1 ml microsomes from 250 mg liver and the metabolic reaction started by addition of cofactors and NADPH. Liver microsomes from rats fed a thiamin-deficient diet had 3 times the capacity to metabolize mestranol as microsomes from rats fed a thiamin-rich diet. The incremental addition of thiamin to the diet depressed mestranol 0-demethylation, NADPH cytochrome c reductase, and cytochrome P-450 content. Pair-feeding experiments indicate that the carbohydrate portion of the food is responsible for decrease in cytochrome c, while thiamin levels are responsible for changes in the other 2.
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PMID:The influence of thiamin deficiency on the metabolism of the oral contraceptive mestranol [3-methoxy-17-ethynyl-1,3,5(10)-estratrien-17 beta-o1] by female rat liver enzymes. 41 82

The effect of mestranol on drug-metabolizing enzymes was studied in female rats receiving either deficient or thiamin-supplemented diets. Rats on the deficient diet showed increased hepatic microsomal activity of aniline hydroxylase, ethylmorphine demethylase, NADPH cytochrome c reductase, and cytochrome P-450. There were also increased concentrations of microsomal docosahexaenoic acid and arachidinic acid. Rats on the thiamin-supplemented diet showed decreased binding of aniline to microsomes, which was due to decreased levels of cytochrome P-450. However, high levels of thiamin decreased the binding of ethylmorphine to P-450. Mestranol increased ethylmorphine and aniline metabolism to a greater degree in animals receiving the thiamin-supplemented diet than those receiving the deficient diet or laboratory feed. However, levels of cytochrome P-450, cytochrome c reductase, or microsomal proteins were not increased, and the binding of aniline to cytochrome P-450 was not affected. Generally, treatment with mestranol decreased the binding of ethylmorphine. It appears that mestranol alters the Type I binding site on cytochrome P-450, but has no effect on the Type II binding site.
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PMID:Influence of the oral contraceptive, menstranol, on drug-metabolizing enzymes of female rats in thiamin-supplemented and deficiency states. 82 34