GROWTH HORMONE AND SOMATOMEDIN BEHAVIOUR IN THE NEWBORN

Abstract

Human growth hormone (HGH) and somatomedin (Sm) concentrations were studied in a group of newborns. Plasma HGH values were 41.17 .+-. 24.26 (SD) ng/ml (14.00-90.00 ng/ml) and the Sm value was 0.59 .+-. 0.43 (SD) U/ml (0.18-1.8 U/ml); the difference between these values and the ones observed in normal adults (2.45 .+-. 2.53 (SD) ng/ml and 1.16 .+-. 0.28 (SD) U/ml respectively) were statistically significant. While GH values were higher than in normal adult controls, somatomedin was significantly decreased. The dissociation between human GH and somatomedin in the newborn may reflect a reduced biosynthesis of the somatomedin-generating system and consequently a lack of feedback control on GH exerted by somatomedin.