Clinical aspects of GH binding proteins.
The high affinity specific binding of 125I-hGH in human serum is attributable to the GH binding protein, which is derived from the extracellular domain of the receptor. Most measurements have been made by gel filtration methods and expressed with a normal human reference serum (RSGHB). The RSGHB is virtually unmeasurable in the cord sera of premature infants and is higher in cord serum of term infants. RSGHB rises progressively in childhood and reaches adult levels after age 20 years. GH deficiency or excess exerts little effect on RSGHB. RSGHB in GH resistance of the Laron-type is virtually undetectable and such measurements are confirmatory of the diagnosis. In African pygmies, the RSGHB fails to rise in late childhood and correlates with decreased IGF-I concentrations and reduced growth velocity at that time. Studies of abnormalities of the GH-BP in nutritional and other medical conditions are in their infancy, but will be greatly aided by simpler assay methods.
Daughaday
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Washington University School of Medicine, Department of Medicine, Saint Louis, Missouri.
Trivedi
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B
D000375:Aging / Q000097:blood; D000818:Animals; D002352:Carrier Proteins / Q000097:blood*; D006130:Growth Disorders / Q000097:blood; D013006:Growth Hormone / Q000097:blood* / Q000172:deficiency; D006801:Humans; D007231:Infant, Newborn
D002352:Carrier Proteins; D013006:Growth Hormone; C051815:somatotropin-binding protein