| This thesis investigated whole body glucose disposal and the adaptive changes in skeletal muscle carbohydrate (CHO) metabolism after a 56-hr high fat/low CHO diet (LCD; 5% CHO, 73% fat, 22% protein). LCD increased the 90-min area under the [glucose] and (insulin] curve (2 and 1.25-fold) during an oral glucose tolerance test (OGTT) (11 g/kg). LCD increased resting pyruvate dehydrogenase kinase (PDK) activity (0.191 ± 0.05 vs. 0.083 ± 0.02 min −1) and decreased the activated form of pyruvate dehydrogenase (PDHa) at rest (0.38 ± 0.08 vs. 0.79 ± 0.10 mmol acetyl-CoA/kg/min) and during OGTT (0.60 ± 0.11 vs. 1.04 ± 0.09) (p < 0.05). LCD did not alter total GLUT-4 protein, total hexokinase (HK) or glycogen synthase (GS) activity. It was concluded that glucose disposal was decreased after LCD and was related to restricted CHO oxidation at the level of PDH activation, secondary to increased PDK activity. |
