The effect of birth on the maturation of hepatic cytochrome(s) P-450 mono-oxygenase and tyrosine aminotransferase activities in the guinea pig.
Mixed coat guinea pigs delivered by Cesarian section 5 days before term were compared to spontaneously delivered full-term animals with respect to the postnatal maturation of hepatic mono-oxygenase activity in vitro toward aniline and p-chloro-N-methylaniline. Tyrosine aminotransferase acitivity was studied in the same preparations as a positive control for birth-related phenomena. Mono-oxygenase activities toward both sustrates increased significantly in both premature and full-term animals during the first 3 postnatal days and approached adult values 72 h after birth. The maturation of tyrosine aminotransferase activity occured in a qualitatively similar fashion. The mechanism through which birth initiates the maturation of drug oxidative capacity is unresolved; the gestational age at which competence to respond to the event of birth is acquired, remains undefined.
The effect of birth on the maturation of hepatic cytochrome(s) P-450 mono-oxygenase and tyrosine aminotransferase activities in the guinea pig. Mixed coat guinea pigs delivered by Cesarian section 5 days before term were compared to spontaneously delivered full-term animals with respect to the postnatal maturation of hepatic mono-oxygenase activity in vitro toward aniline and p-chloro-N-methylaniline. Tyrosine aminotransferase acitivity was studied in the same preparations as a positive control for birth-related phenomena. Mono-oxygenase activities toward both sustrates increased significantly in both premature and full-term animals during the first 3 postnatal days and approached adult values 72 h after birth. The maturation of tyrosine aminotransferase activity occured in a qualitatively similar fashion. The mechanism through which birth initiates the maturation of drug oxidative capacity is unresolved; the gestational age at which competence to respond to the event of birth is acquired, remains undefined.