Absence of glucopenic inhibition of the insulin response to arginine at the onset of diabetes in BB/W rats.
To determine if the inhibiting effect of glucopenia on arginine-stimulated insulin secretion is impaired at the onset of autoimmune diabetes, the insulin response to arginine was studied at 5.6 and 2.8 mmol/l glucose in perfused pancreata isolated from BB/W rats on the first day of diabetes and from age-matched diabetes-prone BB/W rats without diabetes. During glucopenia the baseline insulin secretion was reduced by more than 80% in both groups. However, the arginine-stimulated insulin response in the diabetic group was only 16.5% lower during glucopenia compared to 79.1% lower in the nondiabetic controls. Also, enhancement of the arginine-stimulated glucagon response by glucopenia was modest compared to controls. The results indicated that at the onset of this form of autoimmune diabetes the surviving B cells are, for unknown reasons, hyperresponsive to arginine and that, in contrast to the controls, this response is not inhibited by glucopenia.
Komiya
I
I
Center for Diabetes Research, University of Texas Health Science Center, Dallas.
Unger
R H
RH
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D001327:Autoimmune Diseases / Q000503:physiopathology; D003920:Diabetes Mellitus / Q000503:physiopathology*; D005934:Glucagon / Q000378:metabolism; D005947:Glucose / Q000172:deficiency*; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D010179:Pancreas / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D005934:Glucagon; D001120:Arginine; D005947:Glucose