Arterial-hepatic vein glucose differences in normal and diabetic man after a glucose infusion at rest and after exercise.
The role of the liver in the elimination of infused glucose during recovery after exercise was studied in 5 normal and 4 juvenile diabetic males. The results were compared with those of a resting experiment. The subjects exercised on the bicycle ergometer at a work rate requiring about 70% of their max. Vo2. 0.5 g glucose per kg body weight was infused as a single injection 15 min after the cessation of exercise. Arterial-hepatic vein (a-hv) glucose and lactate differences were measured repetitively both during exercise and throughout the 79 min recovery period. During exercise the a-hv glucose differences were negative and increased more than sixfold in the diabetic subjects and more than tenfold in the non-diabetic subjects. After the glucose infusion the a-hv glucose differences were still negative in the diabetic subjects, indicating a continued net release of glucose from the liver in spite of elevated arterial glucose concentrations. In the non-diabetic subjects there was a small uptake of glucose, accounting for about 0.5% of the total glucose load given. The a-hv lactate differences were larger in the diabetic subjects, indicating a greater dependence upon gluconeogenesis as compared with the non-diabetic subjects. It is concluded that the liver is of no importance in the diabetic subjects and of only slight importance in the non-diabetic subjects for the disposal of infused glucose during the initial hour of recovery after exercise.