Receptor-active growth hormone in Laron dwarfism.

The hepatic radioreceptor assay for hGH has been applied to the detection of hGH in the sera of patients with high growth hormone dwarfism (Laron dwarfism). Substantial quantities of receptor-active hGH were found in the sera of all 7 patients studied. In one patient, arginine infusion elicited a prompt increase in both immunoactive and receptor-active hGH. These observations suggest that circulating hGH in Laron dwarfism is biologically active and support the concept that the disease may be caused by a generalized defect in hGH receptors.