Characterization of insulin-like growth factors and their binding proteins in peritoneal dialysate

Arundhati S Kale, Frances Liu, Raymond L. Hintz, Bonita K. Baker, Eileen D. Brewer, Phillip D.K. Lee, Susan K. Durham, David R. Powell

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

Serum insulin-like growth factors (IGFs), which circulate bound to specific IGF binding proteins (IGFBPs), must exit the intravascular space before acting on target tissues. Little is known about the nature of IGF/IGFBPs in extravascular fluids of patients with chronic renal failure (CRF). Peritoneal dialysate (PD) was studied since, after a short incubation, PD contains proteins which have entered an extravascular space; thus, IGF/IGFBP forms in PD are more likely than serum forms to interact with target tissues. IGF-I and IGF-II, and IGFBPs 1-4, were readily identified by specific immunoassays and/or 125iodine-IGF ligand blotting of simultaneously obtained PD and serum samples from seven CRF children; IGFBP-3 was a major IGFBP in PD as in serum. Where quantitated, IGF and IGFBP levels in PD were approximately 10% of serum concentrations. After separation of PD and serum by size-exclusion chromatography, serum had more IGFBP-3 in 150-kilodalton (kDa) than 35-kDa fractions, while PD had far less IGFBP-3 in 150-kDa than 35-kDa fractions. Immunoblot studies revealed a major 29-kDa IGFBP-3 fragment, in addition to intact 41- and 38-kDa IGFBP-3 forms, in PD and CRF serum; the 29-kDa form predominated in the 35-kDa PD fractions. These data suggest that the 29-kDa fragment is the IGFBP-3 form most likely to modulate IGF effects on target tissues of CRF individuals.

Original languageEnglish (US)
Pages (from-to)467-473
Number of pages7
JournalPediatric Nephrology
Volume10
Issue number4
DOIs
StatePublished - Aug 22 1996
Externally publishedYes

Keywords

  • Chronic renal failure
  • Insulin-like growth factor
  • Insulin-like growth factor binding protein
  • Peritoneal dialysate

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Nephrology

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  • Cite this

    Kale, A. S., Liu, F., Hintz, R. L., Baker, B. K., Brewer, E. D., Lee, P. D. K., Durham, S. K., & Powell, D. R. (1996). Characterization of insulin-like growth factors and their binding proteins in peritoneal dialysate. Pediatric Nephrology, 10(4), 467-473. https://doi.org/10.1007/s004670050141