Effects of diabetes on fructose 2, 6-P2, glucose 1, 6-P2 and 6-phosphofructo 2-kinase in rat liver.

The levels of fructose 2,6-P2 and 6-phosphofructo 2-kinase have been found to be decreased in the liver of both ketotic and non-ketotic diabetic rats, a good correlation between fall of hepatic fructose 2,6-P2, ketonemia and glycemia being observed. The "total" 6-phosphofructo 2-kinase activity and the "active" (non-phosphorylated) from of the enzyme were decreased to a different extent, resulting in a fall of the "active"/"total" activity ratio. Hepatic levels of glucose 1,6-P2 were lowered only in ketotic diabetes. Insulin treatment normalized all the values studied. Insulin administration to control rats decreased the hepatic levels of fructose 2,6-P2 and did not affect glucose 1,6-P2 levels. It also decreased the "active" form of 6-phosphofructo 2-kinase, without significantly altering the "total" activity.