A dynamic role of liver glycogen in alloxan diabetic rats.

The effect of alloxan diabetes on mobilization of the liver glycogen was followed in male rats given one injection of alloxan (200mg/kg). The serum glucose showed a typical triphasic curve, reaching sustained hyperglycemia 24hr after injection. The insulin levels of serum and pancreatic tissue extract remained within normal limits for the first 24hr. The marked decrease in insulin levels from both sources was recorded on the third day. The concentration of liver glycogen, however, was already markedly decreased at the end of one hr after injection, continued at the low contents up to the 12th hr, then it temporaly rose to reach a normal value after 24hr. The outer chain length of the glycogen from one to 12hr after injection was shorter than normal and was close to the phosphorylase limit dextrin. Probably the glucose liberated by the breakdown of the outer chain of the glycogen has led to an early phase hyperglycemia. After 7 days of alloxan-induced diabates, the total hepatic glycogen as well as biochemical structure became reestablished to normal. A further discussion on interaction of alloxan and glucose is given.