Protein levels and phosphorylations of Akt, AS160, hexokinase, AMPK and ACC.

Phosphorylation of Akt and AS160 were assessed by Western blots in muscle biopsies taken before (black bars) and during (grey bars) insulin stimulation after 12 and 72 h of fasting in lean and obese participants. Protein levels of Hexokinase II, as well as phosphorylations of AMPK and ACC were assessed in non-insulin-stimulated muscle biopsies from lean (white bars) and obese participants (crossed bars) after 12 and 72 h of fasting. Data are presented as mean±SD. A and B: Insulin stimulation significantly increased phosphorylation on both pAKt Ser473 and Thr308 regardless of BMI and duration of the fast. We found significant BMI x insulin and fasting x insulin interactions on both phosphorylation sites. Post hoc tests revealed that insulin-stimulated Akt phospylation was lower in obese than lean after 12 h of fasting (PC: We found an interaction between the effect of insulin and fasting (fasting x insulin P = 0.01) on pAS160 Thr642/AS160, and post hoc test revealed a lower insulin-stimulated phosphorylation level in obese after 12 h of fasting compared to lean (P = 0.047). Similar to Akt, the insulin-stimulated levels in obese increased during 72 h of fasting to levels comparable to lean. D: Protein levels of Hexokinase II (relative to total amount of protein) were lower in obese than lean (P = 0.016). E: pAMPK Thr172/AMPK decreased slightly during 72 h of fasting with no difference between groups (fasting effect P = 0.048) F: pACC/ACC was not significantly affected by BMI or fasting. Representative blots in panel D, E and F have been cut to remove insulin-stimulated biopsies. *P+ P# P<0.05 compared to 12 h fast.