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Article
Evidence of insulin-like growth factor binding protein-3 proteolysis during growth hormone stimulation testing
Pediatric Publications and Presentations
  • Benjamin U. Nwosu, University of Massachusetts Medical School
  • Leslie A. Soyka, University of Massachusetts Medical School
  • Amanda Angelescu, University of Massachusetts Medical School
  • Mary M. Lee, University of Massachusetts Medical School
UMMS Affiliation
Department of Pediatrics, Division of Endocrinology; Department of Cell Biology
Publication Date
4-14-2011
Document Type
Article
Subjects
Arginine; Child; Dwarfism; Female; Growth Hormone-Releasing Hormone; Human Growth Hormone; Humans; Insulin-Like Growth Factor Binding Protein 3; Male; Prospective Studies; Puberty
Abstract

OBJECTIVES: 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.

DOI of Published Version
10.1515/JPEM.2011.088
Source
J Pediatr Endocrinol Metab. 2011;24(3-4):163-7. Link to article on publisher's website
Related Resources
Link to Article in PubMed
PubMed ID
21648284
Citation Information
Benjamin U. Nwosu, Leslie A. Soyka, Amanda Angelescu and Mary M. Lee. "Evidence of insulin-like growth factor binding protein-3 proteolysis during growth hormone stimulation testing" Vol. 24 Iss. 3-4 (2011) ISSN: 0334-018X (Linking)
Available at: http://works.bepress.com/mary_lee/15/