title: Development of a chemically defined serum-free medium for differentiation of rat adipose precursor cells.
abstract: Stromal-vascular cells from the epididymal fat pad of 4-week-old rats, when cultured in a medium containing insulin or insulin-like growth factor, IGF-I, triiodothyronine and transferrin, were able to undergo adipose conversion. Over ninety percent of the cells accumulated lipid droplets and this proportion was reduced in serum-supplemented medium. The adipose conversion was assessed by the development of lipoprotein lipase (LPL) and glycerol-3-phosphate dehydrogenase (GPDH) activities, [14C]glucose incorporation into polar and neutral lipids, triacylglycerol accumulation and lipolysis in response to isoproterenol. Similar results were obtained with stromal-vascular cells from rat subcutaneous and retroperitoneal adipose tissues. Stromal-vascular cells required no adipogenic factors in addition to the components of the serum-free medium. Insulin was required within a physiological range of concentrations for the emergence of LPL and at higher concentrations for that of GPDH. When present at concentrations ranging from 2 to 50 nM, IGF-I was able to replace insulin for the expression of both LPL and GPDH. The development of a serum-free, chemically defined medium for the differentiation of diploid adipose precursor cells opens up the possibility of characterizing inhibitors or activators of the adipose conversion process.
mesh_terms: D000273:Adipose Tissue / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001769:Blood; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D050356:Lipid Metabolism; D008071:Lipoprotein Lipase / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014168:Transferrin / Q000494:pharmacology*; D014280:Triglycerides / Q000378:metabolism; D014284:Triiodothyronine / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D007328:Insulin; D014168:Transferrin; D014280:Triglycerides; D014284:Triiodothyronine; D007334:Insulin-Like Growth Factor I; D005993:Glycerolphosphate Dehydrogenase; D008071:Lipoprotein Lipase