[The effect of ethylenethiorea on microsomal liver enzymes in the rat]

The effect of ethylene thiourea on microsomal liver enzymes of rat has been studied by measuring hexobarbital sleeping time and determining aminopyrine-N-demethylase and aniline-hydroxilase activities. Single oral doses of 50, 100 and 200 mg/kg body mass caused significant prolongation of the sleeping time in males. The same effect was caused by 200 mg/kg in females. When ethylene thiourea was administered in the diet at a level of 200 ppm sleeping time in males increased with duration of administration. The duration of narcosis of females increased up to the third week and remained almost constand over the following feeding period. The aminopyrine-N-demethylase and aniline-hydroxylase activities in the liver of male rats were inhibited by single doses of 20 mg/kg or more. Inhibition and subsequent enzyme change depended on dosage.