33 production of labelled igf i by islets cells in culture: biochemical characterization

ABSTRACT It has been shown previously that neonatal and fetal rat islets in culture secrete IGF I as measured by specific radioimmunoassay. We hereby report the partial purification and

biochemical characterization of IGF I produced and secreted by fetal rat islets in culture. Fetal islets were incubated in RPMI 1640 with 1% fetal calf serum with or without (3H) leucine and

(35S) methionine. The conditioned media were acidified to pH 2.7 and chromatographed on Biogel P 100 in acid to separate IGF I from its binding proteins. The quantity of immunoreactive IGF

I present in the media increased with time and plateaud after 48 hours in culture reaching a value of 1 ng IGF I for 300 islets. Part of the total radioactivity (3%) comigrated on Biogel

P100 with immunoreactive IGF I. This fraction was further purified by HPLC on a microbondapak C18 column and eluted with a linear gradient of acetonitrile. Material which comigrated with

pure IGF I (39% acetonitrile) was then purified by chromatofocalisation on PBE 96 column. Part of the radioactivity (30%) eluted at the same basic pH (8.55) than IGF I produced by other

fetal rat cells in culture and was immunoprecipitable by anti-IGFI Ab. In conclusion: labelled material was produced and secreted in vitro by islet cells with identical Mol Weight,

hydrophobicity and isoelectric point than native IGF I. ARTICLE PDF AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Pediatric Endocrinology and Diabetes, INSERM U30 Hôpital des Enfants

Malades, Paris, France R Scharfmann & P Czernichow Authors * R Scharfmann View author publications You can also search for this author inPubMed Google Scholar * P Czernichow View author

publications You can also search for this author inPubMed Google Scholar RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Scharfmann, R., Czernichow, P.

33 PRODUCTION OF LABELLED IGF I BY ISLETS CELLS IN CULTURE: BIOCHEMICAL CHARACTERIZATION. _Pediatr Res_ 24, 522 (1988). https://doi.org/10.1203/00006450-198810000-00054 Download citation *

Issue Date: 01 October 1988 * DOI: https://doi.org/10.1203/00006450-198810000-00054 SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get

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