Differences in liver glycogen-synthase phosphatase activity in rodents with spontaneous insulin-dependent and non-insulin-dependent diabetes.
The activation of glycogen synthase after addition of glucose to isolated hepatocytes became impaired in BB rats after the development of insulin-dependent diabetes. This defect was associated with a decreased hepatic synthase phosphatase activity. Both features correspond closely to previous observations on alloxan-diabetic rats. In contrast, in hyperinsulinaemic db/db mice with a similarly increased plasma glucose concentration (non-insulin-dependent diabetes), the synthase phosphatase activity was essentially normal. We conclude that the decreased hepatic synthase phosphatase activity in insulin-dependent diabetes in rodents is due to the lack of insulin, rather than to the increased intrahepatic glucose concentration.
Bollen
M
M
Department of Biochemistry, Faculty of Medicine, Catholic University of Leven, Belgium.
Keppens
S
S
Stalmans
W
W
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D003922:Diabetes Mellitus, Type 1 / Q000201:enzymology*; D003924:Diabetes Mellitus, Type 2 / Q000201:enzymology*; D005260:Female; D005947:Glucose / Q000494:pharmacology; D006007:Glycogen-Synthase-D Phosphatase / Q000378:metabolism*; D066298:In Vitro Techniques; D008099:Liver / Q000201:enzymology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D051381:Rats; D011913:Rats, Inbred BB; D012016:Reference Values
D010749:Phosphoprotein Phosphatases; D006007:Glycogen-Synthase-D Phosphatase; D005947:Glucose