[Enzymatic activity of xenobiotic metabolism in rats with a varying body allowance of vitamin B1].

Vitamin B1 in rats induced in the liver elevation of activity of metabolic enzymes of xenobiotics bound with membranes (dimethylaniline N-demethylase, aniline n-hydroxylase, aryl esterase). At the same time activity of the cytoplasmatic enzymes alcohol dehydrogenase and glutathione-S-transferase was appreciably lowered. An additional load with thiamine (20 mg/kg) led to a drop in activity of the membrane-bound enzymes. Vitamin B1 deficiency modified the effect of the inductor phenobarbital. Additional administration of vitamin B1 to thiamine-deficient animals normalized the thiamine level in the liver, and activity of hydroxylase, aryl esterase, formaldehyde dehydrogenase, and significantly decreased demethylase activity. In vitamin B1-deficient animals high detergent concentrations significantly suppressed NADH-dichlorophenol-indophenol-reductase activity, while low concentrations activated this enzyme as compared to the control.