Characterization of the insulin and insulin-like growth factor receptors and responsitivity of a fibroblast/adipocyte cell line before and after differentiation.
TA1 cells, like 3T3-L1 cells, undergo a differentiation process in vitro from a fibroblast to an adipocyte phenotype. The TA1 pre-adipocytes were found to have low numbers of insulin receptors but high numbers of receptors for insulin-like growth factors (IGF) I and II. Also, the pre-adipocytes were more responsive to IGF than insulin as measured by either stimulation of glucose or amino acid uptake. After differentiation, the adipocytes had higher numbers of insulin receptors and a better responsitivity to insulin than to IGF-I. These results indicate that insulin-like growth factors are the primary regulators of the pre-adipocytes whereas insulin regulates the adipocytes.
D000273:Adipose Tissue / Q000166:cytology; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D002454:Cell Differentiation; D002460:Cell Line; D005347:Fibroblasts; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000378:metabolism; D051379:Mice; D011972:Receptor, Insulin / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017451:Receptors, Somatomedin
D000596:Amino Acids; D007328:Insulin; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D011972:Receptor, Insulin; D005947:Glucose