Metabolism of territrem a in liver microsomes from wistar rats: 2. Sex differences and regulation with gonadal hormones and phenobarbital.

The aim of the present study was to assess the effects of sex difference on metabolism of territrem A (TRA) by liver microsomes from 7-wk-old Wistar rats. Metabolism of TRA to 2-dihydro-4beta-demethylterritrem A (MA2) through 4beta-hydroxymethyl-4beta-demethylterritrem A (MA1) and 4beta-oxo-4beta-demethylterritrem A (MAX) was observed in intact male rats. However, in intact female rats only MA1 was formed, although the amount of MA, formed in females was much less than in males. Phenobarbital pretreatment enhanced this step and was not affected by gonadectomy. In the gonadectomized rats of both sexes, MA2 was formed from TRA when the animals were further treated by testosterone and was significantly enhanced by treatment with phenobarbital. However, estradiol treatment or estradiol in combination with phenobarbital treatment did not affect MA2 formation from TRA in gonadectomized rats.