Differentiation of 3T3-L1 fibroblasts to adipocytes. Loss of stimulation of uridine and 2-deoxy-D-glucose transport by PGF2 alpha in the course of differentiation of the 3T3-L1 cell line.

Insulin and prostaglandin F₂ (PGF_2α) stimulate undine and 2-deoxy-d-glucose transport by 3T3-L1 and 3T3-C2 cells. Maximal stimulation of both transport systems is achieved with 1.5 μM PGF_2α. Maximal stimulation of uridine transport is achieved with 34 nM (200 ng/ml) insulin. The basal (control) level of uridine uptake is lower in 3T3-L1 than in 3T3-C2 cells, while the basal level of 2-deoxy-d-glucose uptake is slightly higher in 3T3-L1 cells. The stimulatory effect of PGF_2α on both transport systems is abolished in the course of differentiation of 3T3-L1 cells to adipocytes. Removal of the inducers of differentiation (insulin plus indomethacin) from the medium of differentiated cells does not restore responsiveness of either transport system to PGF_2α. In contrast the stimulatory effect of insulin on either transport system is not abolished during differentiation. Treatment of the non-differentiating 3T3-C2 cell line with inducers of differentiation reduces the basal level of 2-deoxy-d-glucose transport by 70% and only slightly decreases the basal level of uridine transport without affecting the stimulatory effect of PGF_2α on either transport system.