Bertil Josephson

A Study of the Enzyme Pattern in Children and Newborn Infants

Comparatively little is known about the development of the concentration of the plasma enzymes in children’s blood, even of those enzymes which are determined routinely in clinical practice. Kove, Goldstein & Wr6blewsky (6) and Stave (11) studied the concentration of serum-glutamic-oxaloacetic acid transaminase (SGOT) and serum-glutamic-pyruvic acid transamipase (SGP-T) in plasma from newborn infants. The alkaline phosphatase in children’s serum has been studied by von Sy dow (13). It is, however, well known that in children the composition of the blood plasma is not identical with that of adults, because the average concentration of several substances of diagnostic interest is different from the corresponding average value in blood from adult man (4). A knowledge of the enzyme concentrations and of the development of the enzyme pattern from birth would be of clinical and ontogenetic interest. A comparison between the enzyme pattern in the plasma from the newborn and the pattern in the mother’s plasma would be of physiological importance. In the present investigation SGO-T, SGP-T, lactic acid dehydrogenase (LD) and serum alkaline phosphatase were determined in the same samples of blood from newborn infants and from a number of children aged one day to seven years. A comparison was also carried out between the enzyme activities in the plasma of a number of mothers and the corresponding activities in plasma from their newborn children. In the newborn children the serum bilirubin concentration also was determined because of the suspicion that their enzyme concentrations could be more or less related to their liver function and to the presence or absence of an icterus neonatorum (1) . A preliminary note about some of our results has been published ( 2 ) .

Age Variations in the Concentration of Non-Protein Nitrogen, Creatinine and Urea in Blood of Infants and Children

Non‐protein nitrogen as well as serum urea and creatinine concentrations were determined in 113 healthy children ranging in age from newborn to six years. The results were compared with those from corresponding analyses of adult blood.

The uric acid concentration in serum from children, newborn infants and mothers after delivery.

During the first week of life the concentration of uric acid in the serum was significantly higher than in normal adults and so was the standard variation. However, it was found that the concentration value from the mother’s sera was equally elevated. Thus it seems likely that uric acid from the mother’s blood was in equilibirium with that of the fetus over the placenta. It is known that amniotic fluid has a higher uric acid concentration than serum. The high concentration in the mother’s blood might be related to an increased formation and metabolism of nucleotides. In children aged more than one year the concentration was not significantly different from that in adult man.