0000000000414238
AUTHOR
Taoufik Masmoudi
Differential effect of hypophysectomy and growth hormone treatment on hepatic glucuronosyltransferases in male rats: Evidence for an action at a pretranslational level for isoforms glucuronidating bilirubin
International audience; The influence of growth hormone (GH) on 4-nitrophenol, bilirubin, testosterone, androsterone and estrone glucuronidation activities was studied in fully activated male rat hepatic microsomes. Sham-operated and hypophysectomized animals were injected with two different dosages of GH, mimicking either the male or female GH secretion pattern. Half the animals received thyroxine and cortisol in concentrations chosen to compensate for the lack of thyroid hormones and glucocorticoids in hypophysectomized rats. GH induced a decrease in several glucuronidation activities: bilirubin glucuronidation in both sham-operated and cortisol/ thyroxine-treated hypophysectomized rats i…
Transcriptional Regulation by Triiodothyronine of the UDP-glucuronosyltransferase Family 1 Gene Complex in Rat Liver
Abstract This study demonstrates that the expression of the phenol UDP-glucuronosyltransferase 1 gene (UGT1A1) is regulated at the transcriptional level by thyroid hormone in rat liver. Following 3,5,3′-triiodo-l-thyronine (T3) stimulation in vivo, there is a gradual increase in the amount of UGT1A1 mRNA with maximum levels reached 24 h after treatment. In comparison, induction with the specific inducer, 3-methylcholanthrene (3-MC), results in maximal levels of UGT1A1 mRNA after 8 h of treatment. In primary hepatocyte cultures, the stimulatory effect of both T3 and 3-MC is also observed. This induction is suppressed by the RNA synthesis inhibitor actinomycin D, indicating that neither induc…