The somatomedin and/or growth-stimulating activity of serum from hypopitui-tary children and short children with normal growth hormone (GH) response to stimulation tests were studied using different bioassays; thymidine incorporation into human activated lymphocytes; sulfate incorporation into chick embryo cartilage: and simultaneous thymidine uptake into the same cartilages. The results showed that lymphocyte assay is highly sensitive to small amounts of serum and is GH-dependenl in children with low GH secretion. On the contrary, the cartilage assays need higher serum concentration and their GH-dcpendence appears only in subjects with normal or low-normal GH secretion. The lack of correlation between the results of the three bioassays suggests that they measure both somatomedins and different scrum factors involved in the regulation of growth.
- Growth hormone deficiency
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Pediatrics, Perinatology, and Child Health