Glucuronidation is low or undectable in embryonic and early fetal tissues and changes to adult levels at rates depending on the acceptor, tissue and species.
The present investigation examined the effects of maternal consumption of alcohol during pregnaney and lactation development of UDP-glucuronosyltransferase activity toward 1-naphthol, 4-nitrophenol 4-methylumbelliferone and bilirubin of neonatal to adult rat liver microsomes.
Conjugation of 1-naphthol and 4-nitrophenol was higher at birth and decreased to adult levels by 21 days of age. Glucuronidation of bilirubin increased from birth to adult activity 21 days of age. Adiministration of alcohol on days 21 after birth increased UDPGT activity toward 1-naphthol and bilirubin compare to control, whereas alcohol decreased the development of UDPGT activity toward 1-naphthol 4-nitrophenol, 4-methylumbelliferone and bilirubin. The concentration of UDP-glucuronic acid was 50% of adult levels at birth and increaed to adult value by 21 days of age. In the administration of alcohol, the concentration of UDP-glucuronic acid was low compare to control. Thus, development of UDPGT ativity toward alcohol appears to be different than that for other acceptors, suggesting there may be a separate UDPGT in rat liver that is responsible for the conjugation of alcohol.
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