Differentiation of adipocyte precursors in a serum-free medium is influenced by glucocorticoids and endogenously produced insulin-like growth factor-I.

Evidence from laboratory and animal studies provides groundwork for understanding mechanisms and potential before human studies continue.

• Level A · Stronger Clinical Evidence
• Level B · Emerging clinical evidence with positive signals
• Level C · Early human research exploring benefits
• Level D · Scientific groundwork from lab and animal studies
• Emerging · Emerging topic under active research

Abstract (original English)

Stromal vascular cells from rabbit perirenal adipose tissue differentiated at a high frequency in a chemically-defined serum-free medium containing insulin, transferrin, tri-iodothyronine and dexamethasone. The omission from the culture medium of dexamethasone resulted in a lack of adipose conversion. Addition of IGF-I increased glycerol-3-phosphate dehydrogenase (GPDH) activity. The conditioned media from adipocyte precursor cells contained measurable quantities of immunoreactive IGF-I as determined by RIA after neutralization of IGF binding proteins interference. Dexamethasone increased IGF-I secretion during the first seven days after plating and decreased IGF-I binding to conditioned media. Three molecular forms of IGF binding proteins (IGFBPs) were identified by Western ligand blots in conditioned media, with M(r) = 40,000, 29,000 and 25,000. The major form (M(r) = 29,000) was decreased by dexamethasone. In contrast, the M(r) = 24,000 form was increased. Specific binding of 125I-labelled IGF-I to rabbit adipocyte precursor cells was more effectively inhibited by unlabelled IGF-I than by unlabelled IGF-II or insulin. The electrophoretic migration of cross linked 125I-IGF-I to microsomal membranes revealed a complex with M(r) = 130,000 under reducing conditions corresponding to the alpha-subunit of the IGF-I receptor. The addition of IGF-I monoclonal antibody to rabbit adipo

Evidence level

Evidence from laboratory and animal studies provides groundwork for understanding mechanisms and potential before human studies continue.

Browse all related research

Filter the research library by this study's title keywords, author, or publication year.