Increased hexokinase/glucose-6-phosphatase ratio in the diabetic kidney as index of glucose overutilization

In mice with streptozotocin-induced diabetes of 3 days' duration, the hexokinase/glucose-6-phosphatase (HK/G6Pase) ratio in the kidney was enhanced by 52% (mean +/- SEM: 0.40 +/- 0.04 vs. 0.26 +/- 0.03; p less than 0.02) compared to control mice as a result of a 25% increase of HK (16.68 +/- 0.93 vs. 13.31 +/- 1.04 nmol/min/mg protein; p = 0.05) and a 17% decrease of G6Pase (42.51 +/- 2.75 vs. 51.25 +/- 1.89; p less than 0.05). In contrast, as expected, the corresponding ratio (HK + glucokinase/G6Pase) was strikingly reduced in the liver. In 9-day diabetic mice, the kidney enzyme changes were much smaller; however, in a chronic disease such as diabetes, even minimal deviations from the normal may lead to significant metabolic changes with time. The enhanced HK/G6Pase ratio in the diabetic kidney suggests an increase in glucose utilization. This may contribute to the increased synthesis of glycogen, glycoproteins (including basement membrane) and RNA (via provision of ribose-phosphate) occurring in the diabetic kidney and supports the view that the kidney (as opposed to other tissues) shows an 'anabolic response' to diabetes.