Hepatic and extrahepatic N-acetyltransferase. Perinatal development using a new radioassay.
We report a sensitive and rapid radioassay method for p-aminobenzoic acid N-acetyltransferase. The principle of this assay involves acetylation of p-aminobenzoic acid with [1-14C] labeled acetyl coenzyme A and direct extraction of enzymically formed radioactive p-acetamidobenzoic acid into nonaqueous scintillation fluid. Using this radiometric assay, hepatic and extrahepatic tissue distributions from rat and rabbit were studied. Rabbit blastocyst and endometrial N-acetyltransferase specific activities were equivalent to hepatic activities. Perinatal development studies in rats and rabbits revealed that fetal and neonatal animals are capable of N-acetylation. Rat liver developmental studies exhibited two peaks of activity with the first peak occurring in the late fetus followed by a second peak 3 days after birth. Rabbit fetal and neonatal enzyme activity increased to adult levels by the second week after birth in liver and gut, however, lung showed a different developmental pattern. These studies demonstrate that fetal extrahepatic tissues, like adult tissues, play an important role in N-acetylation.
D000123:Acetyltransferases / Q000032:analysis / Q000378:metabolism*; D062365:Aminobenzoates; D000818:Animals; D002729:Chloromercuribenzoates / Q000494:pharmacology; D005069:Evaluation Studies as Topic; D005333:Fetus; D005865:Gestational Age; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D008345:Manganese / Q000494:pharmacology; D008722:Methods; D009928:Organ Specificity; D011817:Rabbits; D051381:Rats; D015032:Zinc / Q000494:pharmacology
D062365:Aminobenzoates; D002729:Chloromercuribenzoates; D008345:Manganese; D000123:Acetyltransferases; D015032:Zinc