title: The influence of triiodothyronine (T3) on the postnatal development of drug metabolism in rat liver.
abstract: The influence of T3 on some cytochrome P-450-dependent biotransformation reactions (ethylmorphine N-demethylation, ethoxycoumarin O-deethylation and ethoxyresorufin O-deethylation) was investigated in rats of different ages. After T3 administrations on 3 consecutive days to rats of different ages, on the 4th day ethylmorphine N-demethylation rate was diminished in all age groups. On the contrary, ethoxyresorufin and ethoxycoumarin O-deethylation rates were considerably enhanced, preferentially in 33-day-old animals. The P-450 concentration was increased to a smaller degree. After T3 treatment on the first 8 days of life long-term effects on ethylmorphine N-demethylation were observed. Low T3 doses accelerated this reaction in 33- and 60-day-old rats. Ethoxycoumarin O-deethylation was not influenced. T3 administrations cannot diminish age-differences in drug metabolism.
mesh_terms: D000375:Aging; D000818:Animals; D001711:Biotransformation; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D066298:In Vitro Techniques; D008099:Liver / Q000254:growth & development / Q000378:metabolism*; D008297:Male; D006899:Mixed Function Oxygenases / Q000378:metabolism; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014284:Triiodothyronine / Q000494:pharmacology*
chemical_list: D004364:Pharmaceutical Preparations; D014284:Triiodothyronine; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases