Non-suppressible insulin-like activity in Laron's syndrome.
Severe growth retardation is found in patients with high levels of growth hormone and low sulphation factor activity or somatomedin. Also non-suppressible insulin-like activity (NSILA-s) has been found to be very low in a patient with this condition as measured by bioassay, protein binding assay and radioimmunoassay and to be below activities found in hypopituitary patients. Partially purified NSILA-s restored the ability of serum to increase sulphation activity although full restitution may still depend on other factors. These findings support the hypothesis that NSILA-s belongs to the family of somatomedin and thus is involved in promoting growth, and that low activity of these growth factors is a primary cause of the growth retardation found in these patients.
D000818:Animals; D001681:Biological Assay; D002356:Cartilage / Q000032:analysis; D002642:Chick Embryo; D002648:Child; D002850:Chromatography, Gel; D006130:Growth Disorders / Q000097:blood*; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D008297:Male; D008970:Molecular Weight; D011485:Protein Binding; D011863:Radioimmunoassay; D013002:Somatomedins / Q000032:analysis / Q000097:blood* / Q000378:metabolism*; D013577:Syndrome
D013006:Growth Hormone; D013002:Somatomedins