Activities of hepatic enzymes in spontaneous diabetes rats produced by selective breeding of normal Wistar rats.

Acitivites of the hepatic enzymes were determined in spontaneous diabetes rats. The activities of the enzymes were compared with those in normal rats and in streptozotocin diabetic rats. In the spontaneous diabetes rats, glycogen phosphorylase and glycogen synthase were 14.6 +/- 0.6 and 1.73 +/- 0.15 U respectively. The activities of both the enzymes were significantly increased. In the spontaneous diabetes rats glucokinase was 3.82 +/- 0.5 U showing a significant increase. On the contrary, the activity of the enzyme was decreased in the streptozotocin diabetic rats. Glucose-6-phosphatase was increased both in the spontaneous diabetes rats and in the streptozotocin diabetic rats. Fructose-1,6-diphosphatase was increased in the spontaneous diabetes rats. Glucose-6-phosphate dehydrogenase was increased in the spontaneous diabetes rats and decreased in the streptozotocin diabetic rats. In the spontaneous diabetes rats phosphofructokinase showed a reduction of the activity and glucose-6-phosphate dehydrogenase was elevated. These findings are consistent with the results of activities of the hepatic enzymes in adult-onset diabetic patients. These patterns of the hepatic enzymes in the spontaneous diabetes rats were different from those in the streptozotocin diabetic rats. From these patterns of activities of the hepatic enzymes, the spontaneous diabetes rats produced by repetition of selective breeding according to Goto et al. (1975,1976) are an excellent model of human adult-onset diabetes.