Effect of acute alcohol intoxication on 4E-BP1 phosphorylation and the formation of the active eIF4F complex in skeletal muscle from young and mature rats. Groups are the same as described in Figure 1. Gastrocnemius was collected 2.5 h after administration of alcohol or saline (control). Insert above each graph: representative Western blots. Panels A and B: densitometric analysis of immunoblots of γ-phosphorylated 4E-BP1 and total eIF4E in muscle homogenate, respectively, Panels C and D: eIF4E was immunoprecipitated (IP) and the amount of 4EBP1 and eIF4G bound to eIF4E was assessed by immunoblotting (IB). There was no age- or alcohol-induced change in total eIF4E in the immunoprecipitate (data not shown). In panel C, the α- and β-isoforms of 4E-BP1 are indicated. Values (means ± SEM) are expressed relative to the young saline-treated control group. Sample size was 10, 10, 6, 7, 9, and 9 for the six groups, respectively. Values with different letters are significantly different from each other, P < 0.05. Values which share a common letter are not statistically different.