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Figure 2
HFD feeding for 1 d induces insulin resistance in the brain-liver circuit. Rats were fed NC or HFD (171% of the energy of NC) for 1 d. After 5 h of fasting, vehicle (veh) or 4 μU insulin (ins) was infused into the MBH for the entire 6-h duration of the clamp study. (A) Clamp protocol. Equilibration period, 0–120 min; basal period, 120–240 min; insulin clamp period, 240–360 min, during which systemic insulin and glucose were continuously infused and the rate of the latter was adjusted to maintain euglycemia. (B) Glucose infusion rate required to maintain euglycemia during the clamp period. (C) HGP during the basal and clamp periods. (D) Clamp/basal HGP suppression ratio. (E) Peripheral glucose uptake during the clamp period. *P < 0.05; **P < 0.01; ***P < 0.001.