Résumé
The effect of the antidiabetic agent vanadyl sulphate (VOSO
4) on the endocrine pancreas function of normal rats was studied using the isolated pancreas preparation. A short-term (8 days) i.p. treatment (15 mg/kg per day) resulted in attenuation of high glucose-stimulated insulin release, at day 9 but also at days 19, i.e., after full recovery of appetite and weight, while blood and pancreas vanadium concentrations were still elevated. Six months of oral VOSO
4 treatment (0.75 mg/ml in drinking water) resulted in elevated vanadium concentrations while glucose-stimulated insulin release was attenuated as compared to pair-fed animals. Conversely, when directly perfused in pancreas, VOSO
4 potentiated glucose-stimulated insulin release. These apparently opposite effects may be related to the ability of VOSO
4 to exert both peripheral insulinomimetic effects – leading to chronic reduction in insulin demand
–, and a direct pancreatic insulinotropic activity.