Abstract
By using an in situ rat hindquarter perfusion, we evaluated ketone body utilization and its metabolic effects in the resting muscle of 24h fasted normal and streptozotocin (STZ)-diabetic rats. Under the perfusion with ketone body-supplementation (1 mM each of acetoacetic acid (AcAc) and 3-hydroxybutyric acid (3-OHB)), the AcAc and 3-OHB uptake of STZ-diabetic rats was significantly (P<0.05) smaller than that of normal rats. This might be explained by the low enzyme activity of 3-oxoacid CoA transferase demonstrated in the hindlimb muscles of STZ-diabetic rats and this reduced ketone body uptake would be one of the causes of the development of diabetic ketoacidosis. The glucose uptake and the phosphofructokinase (PFK) activity of normal rats were significantly (P<0.05) higher than those of STZ-diabetic rats. In both normal and STZ-diabetic rats, the glucose utilization and PFK activity of the muscles in the ketone body-supplemented condition were significantly (P<0.05) lower than those in the non-supplemented condition. This inhibition of glucose utilization by ketone bodies should be due to the mechanism by which the oxidation of ketone bodies inhibits PFK in the muscle.
