Abstract
The purpose of this study was to compare the bioactivity (SM) and the binding activity (ILA) of somatomedin in 11 children with growth retardation and persistent GH secretion after cranial irradiation for medulloblastoma or head and neck tumors. Children aged 6-12 yr, first seen 16-54 mo after irradiation were investigated over periods of 6-36 mo. Each patient at invervals of 3 mo or more underwent 2 to 4 arginine-insulin tests with determinations of GH, SM by the porcine cartilage bioassay and ILA by RRA after plasma acid gel filtration. GH peak values were distributed from severe (5 ng/ml n = 5 ), to partial (5-10 ng/ml n = 13) or normal range (10 ng/ml n = 7 ). All SM values were low (<0.5 U/ml). Mean ILA was lower than control but significantly higher than values obtained in idiopathic hypopituitarism (IH)
In conclusion, in children with growth retardation after cranial irradiation impaired GH secretion was associated with SM in the hypopituitary range while ILA was only slightly decreased. This is another clinical example of the difficulty in evaluating somatomedin activities in growth retardation.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Rappaport, R., Czernichow, P., Prevot, C. et al. Discrepancy between the bioactivity and the binding activity of somatomedin in patients with abnormal growth hormone secretion after cranial irradiation. Pediatr Res 15, 1541 (1981). https://doi.org/10.1203/00006450-198112000-00035
Issue Date:
DOI: https://doi.org/10.1203/00006450-198112000-00035