Browsing by Author "Udeagha, Udeagha Alichi"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Open Access
    The effect of regioselective Hepatotoxins on the metabolism of Cimetidine and Metyrapone
    (Obafemi Awolowo University, Ile Ife, Nigeria, 1985) Udeagha, Udeagha Alichi
    tetrachloride 24 hr before the administration of either cimetidine or metyrapone. Urine samples were collected after 24 hr and analyzed for the drugs and their metabolites. All the hepatotoxins increased the level of cimetidine sulphoxide formation in the male rats. Centrolobular necrotic agents thioacetamide and carbon tetrachloride inhibited the N-oxidation and keto reduction of metyrapone in both sexe. and also decreases the sulphoxidation of cimetidine in the female rats only. Studies with these hepatotoxic agents indicated. that the S-oxidation of cimetidine n male' rats are possibly not catalyzed by a cytochrome P-1.50 dependent monooxygenase system but by the microsomal FFAD--containing monooxygenase system. Sex difference in these reactions was noted and the possible involvement of cytochrome P-450 female demonstrated. The keto reduction an%: the -oxidation of metyrapone was demonstrated to be via a cytochrome P-450 dependent monooxygenase in both sexes. The N-oxidation and keto reduction of metyre one, the sulphoxida oxidation of cimetidine (female rats only) and the 5-hydroxymethyl-cimetidine formation were shown to o _e r in the centrolobular region of the liver. The FAD-containing sulphoxidase was shown to be evenly distributed within the liver lobule.