Fructose 2,6-bisphosphate and insulin stimulation of glycolysis in 3T3-L1 adipocytes.

1. Insulin is able to stimulate lactate production and to enhance fructose 2,6-bisphosphate (Fru-2,6-P2) content in 3T3-L1 adipocytes. 2. Phorbol 12-myristate 13-acetate is more efficacious than insulin in rising Fru-2,6-P2 content and less effective in the stimulation of glycolysis. 3. 3T3-L1 adipocyte 6-phosphofructo-l-kinase appears to be very sensitive to exogenous Fru-2,6-P2. 4. Insulin treatment does not affect the maximum activity of 6-phosphofructo-1-kinase whereas it markedly increases the affinity of pyruvate kinase for phosphoenolpyruvate. 5. The role of Fru-2,6-P2 in the insulin induced enhancement of glycolytic flux is discussed.