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84 UDP-Glucuronyl Transferase

1967; Springer Nature; Volume: 1; Issue: 3 Linguagem: Inglês

10.1203/00006450-196705000-00091

1530-0447

Elias Halac, Pamela Weiss, Joseph Dancis,

Growth Hormone and Insulin-like Growth Factors

We have reevaluated the capacity of newborn rat livers to conjugate bilirubin and p-nitrophenol with glucuronic acid after activation of liver homogenates with EDTA and utilizing improved assaying conditions as previously reported. We have found that the newborn liver conjugates p-nitrophenol at levels similar to adult male rats while bilirubin conjugation is not detected before the 12th hour of life. Phenobarbital injections to the mother during the last 8 days of pregnancy induced the prenatal development of this enzyme and 2-hour-old fetuses had about 1/3 of the adult level of bilirubin UDP-glucuronyltransferase activity. The capacity to conjugate p-nitrophenol was not significantly altered by phenobarbital. The activation of UDP-glucuronyltransferase by EDTA has been studied by electron microscopy. We have found that EDTA induces the conversion of rough endoplasmic reticular membranes into smooth membranes. This finding correlates significantly with the increase of hepatic smooth membranes after birth and that induced by phenobarbital administration. (SPR)