title: Insulin-like growth factor 1 induction of differentiation of porcine preadipocytes.
abstract: The role of insulin-like growth factor I (IGF-1) in the development of the porcine preadipocyte was studied. Primary cultures of stromal-vascular cells (containing preadipocytes) were derived from s.c. adipose tissue of pigs at 1 d of age by enzyme digestion and centrifugation. Cells were cultured for a total of 15 d. Cells were exposed to IGF-1 at concentrations of 0, 5, 25 or 50 ng/ml medium during one of four time periods: d 1-15, d 1-5, d 13-15, or 4 h on d 15 of culture. IGF-1 had a mitogenic effect on cells during the first three time periods as determined by coulter counting. IGF-1 induced the enzymatic differentiation of porcine preadipocytes following exposure for either the entire 15 d of culture or for only 48 h (d 13-15) after confluency had been attained (d 5). Histochemically, lipid accumulation over time paralleled changes in enzyme activity. Incubation of IGF-1 with the cell cultures during the logarithmic phase of growth (d 1-5) or for 4 h on d 15 did not affect enzyme activity. These data indicate that IGF-1 can induce the differentiation of porcine preadipocytes after the cells leave the logarithmic phase of growth through action on post-confluent events.
authors.affiliation: Ohio State University, Columbus.
authors.forename: T G
authors.initials: TG
authors.lastname: Ramsay
authors.forename: M E
authors.initials: ME
authors.lastname: White
authors.forename: C K
authors.initials: CK
authors.lastname: Wolverton
mesh_terms: D000273:Adipose Tissue / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D000818:Animals; D002452:Cell Count / Q000662:veterinary; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division; D002478:Cells, Cultured; D006651:Histocytochemistry; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D050356:Lipid Metabolism; D008297:Male; D013002:Somatomedins / Q000494:pharmacology*
chemical_list: D013002:Somatomedins; D007334:Insulin-Like Growth Factor I