Fig. 5

Effect of inhibitors of insulin signaling on glucose transport and PAI-1 mRNA expression in insulin-resistant 3T3-L1 adipocytes. Fully differentiated 3T3-L1 adipocytes were treated for 3 days with 3 ng/ml of recombinant murine TNF-α to render them insulin resistant. (A) The insulin-resistant cells were either left untreated or were pretreated for 15 min with DMSO or with wortmannin, rapamycin, and PD98059 at the indicated doses. Uptake of 2-deoxyglucose was then measured in the absence or presence of 100 nM insulin as described in Materials and Methods. (B) Insulin-resistant 3T3-L1 adipocytes were left untreated or were pretreated for 1 hr with DMSO or with wortmannin, rapamycin, and PD98059 at the indicated doses. The cells were then treated with 1000 nM insulin for 3 hr and PAI-1 mRNA expression was measured using quantitative RT-PCR. For panels A and B, n = 6 ± SD. I, insulin; wort, wortmannin; Rap, rapamycin; PD, PD98059.