different ontogenic patterns seem to exist between monooxygenase activities : if the overall cytochrome p 450 concentration , aniline hydroxylase , benzphetamine demethylase , epoxide hydrolase , and glutathione s-transferase activities reach about the half of adult values as early as 15-25 weeks of gestational age , the metabolism of benzo ( a ) pyrene , ethoxycoumarin , and testosterone in position 6 beta is very low in these foetuses , whereas the 16 alpha hydroxylation of dehydroandrosterone is higher than in adult human liver .
C0010762
cytochrome p 450
C0025519
metabolism