Evidence of insulin-like growth factor binding protein-3 proteolysis during growth hormone stimulation testing
UMass Chan AffiliationsDepartment of Cell Biology
Department of Pediatrics, Division of Endocrinology
Document TypeJournal Article
Growth Hormone-Releasing Hormone
Human Growth Hormone
Insulin-Like Growth Factor Binding Protein 3
Endocrinology, Diabetes, and Metabolism
MetadataShow full item record
AbstractOBJECTIVES: The ternary complex is composed of insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-3 and acid labile subunit (ALS). Growth hormone (GH) promotes IGFBP-3 proteolysis to release free IGF-I, ALS, and IGFBP-3 fragments. Our aim was to determine whether elevated GH levels during GH stimulation testing would trigger IGFBP-3 proteolysis. DESIGN: This prospective study of 10 short prepubertal children (height standard deviation score -2.37 +/- 0.31) used arginine and GH releasing hormone stimulation to study dynamic changes in the ternary complex moieties. IGFBP-3 was measured in two assays: a radioimmunoassay (RIA) that detects both cleaved and intact IGFBP-3; and an immunochemiluminescence assay (ICMA) that detects only intact IGFBP-3. RESULTS: IGFBP-3 measured by RIA increased by 19% (p < 0.05), while IGFBP-3 measured by ICMA did not significantly increase (6.1%). CONCLUSION: The significant increase in IGFBP-3 measured by RIA, but not ICMA, provides evidence of IGFBP-3 proteolysis during acute GH stimulation.
SourceJ Pediatr Endocrinol Metab. 2011;24(3-4):163-7. Link to article on publisher's website
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/43757
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