Short-term fatty acid effects on adipocyte glucose uptake: mechanistic insights

The modulation of insulin sensitivity in visceral fat tissue could be important in the treatment of Type 2 diabetes mellitus. Selected fatty acids may impact on insulin-stimulated and basal glucose uptake in adipocytes, thus isolated rat epididymal adipocytes were exposed to 100 microM oleic, arachidonic, eicosapentaenoic, docosahexaenoic or stearic acids and insulin (15 nM) or vehicle for 30 min. Glucose uptake was quantified by measuring uptake of 3H-deoxyglucose/mg adipocyte protein/min. Where appropriate, inhibitors were included to elucidate the mechanisms involved. In this model, insulin stimulated glucose uptake with 62+/-7%. All fatty acids tested, except for stearic acid, depressed insulin-stimulated glucose uptake by an average of 33+/-4.2%. On the other hand, all fatty acids tested except stearic and arachidonic acids, stimulated basal glucose uptake with an average of 34+/-8.1%. Inhibitor studies showed the involvement of prostaglandins, lipoxins, protein kinase C and tyrosine kinase in these processes.