Enhanced peripheral glucose utilization and suppressed hepatic glycogen synthesis in KK mice treated with islet-activating protein (IAP).

Effect of islet-activating protein (IAP) on glucose utilization of peripheral tissues and glycogen synthesis of the liver was investigated in diabetic KK mice. The 14C-content of diaphragm glycogen following the injection of [U-14C] glucose was much less in KK mice than in dd/Y mice, and it was restored to normal in KK mice treated with IAP. The enhanced glucose utilization in these mice was completely abolished by the injection of anti-insulin serum. Glycogen synthesis of the liver after glucose load was also less in KK mice than in dd/Y mice, and it was clearly suppressed in both groups of mice by IAP treatment. It was concluded that improved glucose tolerance of IAP-treated KK mice was mostly due to enhanced glucose utilization of peripheral tissues secondary to increased insulin secretion induced by IAP injection.