ABSTRACT
The effect of continuous amylin infusion on glucose tolerance in rats and the effect of amylin on glucose-stimulated insulin secretion from isolated rat pancreatic islets were sudied. Three groups of animals formed the study of glucose tolerance: Group 1 received salined infusion; Group2 , amylin at 2. 6 nmol?kg-1/h;and group 3,amylin at 26 nmol**kg-1/h. The total infusion time was 60 min. The insulin level and serum glucose were not altered at lower dose of amylin. However glucose levels markedly rose at 2.7,12 min. after beginning IVGTT, without significant change of insulin levels in group 3. The response of insulin to 16. 7 mol glucose-stimulated isolated rat pancretic islets was singnificantly inhibiled by the addition of amylin 10 umol.
ABSTRACT
Sodium orthovanadate is one of vanadate salts. When administered orally to STZ-induced diabetic rats, sodium orthovanadate may stimulate glucose uptake and. metabolism and made them normoglycemic. However, the blood glucose levels of normal rats treated with sodium orthovanadate did not change despite their plasma insulin levels decreased. The insulin-like effect of sodium orthovanadate on carbohydrate metabclism was not due to direct stimulation of insulin secretion, because the plasma insulin concentration of vanadate-treated STZ-rats remained lower and insulin secretion of isolated pancreas perfused with solution containing sodium orthovanadate was smilar to that of controls.