Reduction of glycogen stores in a rat model of chronic hyperinsulinism.
To assess a suitable model for the study of the mechanisms of development of insulin resistance in vivo, liver and muscle glycogen levels (as a metabolic index of tissue insulin sensitivity) were investigated in rats with functioning islet cell adenomas induced by streptozotocin and nicotinamide. These rats have basal moderate hyperinsulinemia and hypoglycemia and show a remarkable increase in insulin secretion after glucose administration. Plasma glucagon concentrations are normal. Nevertheless, in tumor-bearing rats, a reduction of tissue glycogen stores occurs, related to plasma glucose concentrations, and liver glycogen fails to increase even after a glucose load. The lack of excess fat in tumor-bearing rats also suggests a certain insulin insensitivity of the adipose tissue and distinguishes this model of chronic hyperinsulinism from other reported models, such as genetically obese animals.
Masiello
P
P
Bergamini
E
E
D000311:Adrenal Glands / Q000473:pathology; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002908:Chronic Disease; D004195:Disease Models, Animal; D005934:Glucagon / Q000097:blood; D006003:Glycogen / Q000378:metabolism*; D006946:Hyperinsulinism / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008099:Liver / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000378:metabolism; D009929:Organ Size; D051381:Rats; D011919:Rats, Inbred Strains
D001786:Blood Glucose; D007328:Insulin; D006003:Glycogen; D005934:Glucagon