[Effect of thiamine on the activity of liver endoplasmic reticulum enzymes metabolizing drugs].

Experiments on mongrel albino male rats have shown that a single subcutaneous administration of thiamine in a dose of 200 mg/kg raises in the liver microsomes the level of cytochromes P-450 and B5 and increases the activity of aniline-n-hydroxylase ethylmorphine and aminopyrine-N-demethylase. Administration of the vitamin in a dose of 30 mg/kg for 64 days forces down the cytochrome P-450 and the aniline-n-hydroxylase and ethylmorphine-N-demethylase levels. In vitro tests the P-450 and B5 cytocrome levels and the activity of ethylmorphine-N-demethylase in the liver microsomes start to decrease at the thiamine concentration of 1 mM and of aminopyrine-N-demethylase of 4 mM.