title: The defective glucose sensitivity of the B cell in non insulin dependent diabetes. Improvement after twenty hours of normoglycaemia.
abstract: In non insulin dependent diabetics (N.I.D.D.) of normal body weight, the acute insulin response to glucose is defective while that to pharmacologic agents such as tolbutamide is less impaired. This specific B-cell insensitivity to glucose results from unknown and perhaps multiple mechanisms. Hyperglycemia may be itself aggravate this phenomenon. To test this hypothesis acute insulin release (delta I: sum of increment at 2, 5, 10 min) after intravenous and tolbutamide injection was studied in 5 N.I.D.D. with fasting blood glucose averaging 12.1 mM/I (range 10.7-13.7) before and after 20 hours of glycemic normalization by an artificial pancreas. Intravenous injection of .3 g/k glucose did not elicit an acute insulin or C-peptide response, but following Tolbutamide (20 mg/kg) delta I was 44 +/- 21 microU/ml and delta C-peptide 0.84 +/- 0.37 nM/I. After 20 hr of normoglycemia a response to glucose was apparent (delta I 60 +/- 24 and delta CP 0.86 +/- 26) that to Tolbutamide was unchanged (delta I 58 +/- 26 and delta CP 0.97 +/- 0.27). These results suggest that 20 hr of normoglycemia improve significantly the "glucoreceptor" function of the B-cell in N.I.D.D.
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000097:blood; D003920:Diabetes Mellitus / Q000503:physiopathology*; D005215:Fasting; D005260:Female; D005947:Glucose; D006801:Humans; D007328:Insulin / Q000097:blood; D007515:Islets of Langerhans / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014044:Tolbutamide
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D014044:Tolbutamide; D005947:Glucose