Bioassay of growth-stimulating activity of serum: comparison of lymphocyte and cartilage assays in normal and growth hormone-deficient children.
The somatomedin and/or growth-stimulating activity of serum from hypopituitary 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-dependent in children with low GH secretion. On the contrary, the cartilage assays need higher serum concentration and their GH-dependence 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 serum factors involved in the regulation of growth.
D000293:Adolescent; D000818:Animals; D002356:Cartilage / Q000378:metabolism*; D002642:Chick Embryo; D002648:Child; D002675:Child, Preschool; D005260:Female; D013006:Growth Hormone / Q000172:deficiency* / Q000378:metabolism; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D013002:Somatomedins / Q000097:blood* / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism
D013002:Somatomedins; D013431:Sulfates; D013006:Growth Hormone; D013936:Thymidine