C14 studies in carbohydrate metabolism: V. Glucose metabolism in alloxan-diabetic rats

Abstract

A six-compartment model has been designed to approximate the pool system as it is conceived to exist for glucose, bicarbonate and equilibrating metabolites in the intact rat. The rates of internal exchange and external egress of glucose have been calculated for normal and diabetic animals. The turnover of glucose, exclusive of urinary excretion, was approximately twice as high in diabetic animals as in normal animals in both dietary states. Of the total turnover of glucose approximately one-third was recycled (glucose → nonglucose → glucose) in fasted animals, both normal and diabetic, and one-half in postabsorptive animals. Oxidative disposal of glucose in the postabsorptive state tended to be lower in diabetic than in normal animals, but in the fasted state the rate was higher in fasted diabetic rats. Whereas in normal animals the oxidative rate was higher in the postabsorptive state than during fasting, this was not true for diabetic animals. Nonoxidative, nonexcretory disposal of glucose was higher in diabetic rats, whether fasted or postabsorptive.