LPHC (6% protein; 74% carbohydrate) or control (17% protein; 63% carbohydrate) diets were administered to rats (鈭?00聽g) for 15聽d. Total FA and G3P synthesis and the synthesis of FA and G3P from glucose were evaluated in聽vivo by 3H2O and 14C-glucose. Sympathetic neural contribution for FA synthesis was evaluated by comparing the synthesis in denervated (7聽d before) IBAT with that of the contralateral innervated side. The insulin signaling and 尾3 adrenergic receptor (尾3-AR) contents, as well as others, were determined by Western blot (Student's t test or analysis of variance; P聽鈮ぢ?.05).
Total FA synthesis in IBAT was 133% higher in the LPHC group and was reduced 85% and 70% by denervation for the LPHC and control groups, respectively. Glucose uptake was 3.5-fold higher in the IBAT of LPHC rats than in that of the control rats, and the contribution of glucose to the total FA synthesis increased by 12% in control rats compared with 18% in LPHC rats. The LPHC diet increased the G3P generation from glucose by 270% and the insulin receptor content and the p-AKT insulin stimulation in IBAT by 120% and reduced the 尾3-AR content by 50%.
The LPHC diet stimulated glucose uptake, both the total rates and the rates derived from glucose-dependent FA and G3P synthesis, by increasing the insulin sensitivity and the sympathetic flux, despite a reduction in the 尾3-AR content.