Figure 4

p44/42 MAPK in H441 cells treated with or without insulin (2.5 μg/ml). Equal amounts of protein homogenate from each condition were separated by electrophoresis then probed by immunoblotting. Protein molecular weight standards (kDa) are shown on the right. The data are representative of 3 experiments. (A) Total MAPK (p44 and p42, arrows). The total amount of MAPK was not altered by insulin treatment at any time-point. (B) Phospho-p44 and p42 MAPK (P-p44 and P-p42, arrows). Insulin had no effect on the phosphorylation of p44/42 MAPK when the cells were incubated with insulin for 15 min to 2 hours. After a 16-hour incubation, insulin decreased the levels of phospho-p44/42 MAPK. MAPK = mitogen-activated protein kinase