Secretion of insulin-like growth factor-II into bile of rats of different ages

Anthony F Philipps, Bohuslav Dvořák, Gary G. Anderson, James G. Grille, Catherine S. Williams, Otakar Koldovský

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1 Scopus citations


Bile from rats of different ages (suckling 10-12 days; weanling 30-33 days, and adult 60-70 days) was collected and studied for the presence of immuno- and receptor-assayable insulin-like growth factor-II (IGF-II) concentrations. Concentrations of RIA IGF-II in bile were highest in suckling rats (230 ± 38 ng/ml) and lowest in adults (47 ± 7 ng/ml). These concentrations were approximately twice those of the bile IGF-I concentration in sucklings, as measured in a previous study. Selected bile samples were also assayed using a competitive binding assay with a crude preparation of adult rat liver membranes bearing the IGF-II receptor. These studies confirmed the presence of receptor- (as well as immuno-) active IGF-II in bile. Since bile flow rates increased dramatically after the suckling period, bile delivery rates of IGF-II were normalized as picograms per gram body weight per hour. When such calculations were done, bile IGF-II delivery rates to the small intestine were highest in sucklings and weanlings in comparison to adult rats. Thus non-enterically derived (milk- and bile-borne) IGF-II delivery to the suckling small intestine can be approximated at roughly 1 μg/day. Unlike IGF-I, intravenously injected IGF-II could not be detected in suckling bile, suggesting a predominantly hepatic origin. From this study we conclude that there exists a significant delivery of receptor-active IGF-II to the gastrointestinal tract of rats of all ages. Copyright (C) 2000 S. Karger AG, Basel.

Original languageEnglish (US)
Pages (from-to)106-112
Number of pages7
JournalBiology of the Neonate
Issue number2
StatePublished - Aug 2000


  • Bile
  • Gastrointestinal tract
  • Insulin-like growth factors
  • Suckling

ASJC Scopus subject areas

  • Developmental Biology
  • Pediatrics, Perinatology, and Child Health


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