The activity of glutamic oxaloacetic transaminase (GOT) in the serum was determined by the spectrophotometric method in 63 normal term newborn infants, varying from birth to 11 days of age. The normal range of activity in the newborn period varied from 13 to 105 units (with the exception of one infant in whom the level was 160 units). This is a considerably wider range than that of 5 to 45 units found in normal adults. Allowing for an error of about ±10% inherent in the method of determination of GOT, activity as great as approximately 120 units, which in adults would be indicative of some pathologic state, must be considered physiologic in the newborn infant.
The activity of GOT was not related to the age of the infant within the neonatal period studied, and varied widely in different infants for each day of age, without any distinctive pattern. Variations of the activity of GOT in specimens of cord blood studied ranged below 59 units, which was lower than for any other day of the neonatal period adequately investigated. No infants were studied repeatedly.
No relation was found between the concentration of bilirubin and the activity of GOT in the serum.