The Effects of Alloxan Diabetes, Insulin and Epinephrine on Glucose-6-phosphate Dehydrogenase from Rat Liver and Brain

Abstract

The control of glucose-6-phosphate dehydrogenase (G6PD) activity of the liver and brain were studied in normal and alloxan diabetic rats. Fasting decreased G6PD activity in brains and livers of normal rats significantly, but these decreases were reversed by placing the rats on a sucrose-rich diet. Injection of insulin into normal 48h fasted rats had no significant effect on G6PD activity after 15 min. However, epinephrine significantly decreased liver G6PD activity by 17%, 7.5 min. after injection. Epinephrine had no effect on brain G6PD activity.

In fed alloxan diabetic animals, the G6PD activity was found to be about 50% of that found in normal rats. Treatment of diabetic rats with protamine insulin partially reversed the decrease in G6PD activity caused by alloxan diabetes. It is concluded that insulin and epinephrine are important for the regulation of G6PD activity in vivo.