ObjectiveThe aim of this project was to evaluate the RAS inhibition on protein expression and activation of components of NAD(P)H oxidase enzyme in pancreatic islets of experimental model of insulin resistance.Methods and ResultsInsulin resistance was induced by neonatal treatment with monosodium glutamate (MSG). MSG and controls (CTL) received losartan (30mg/Kg/dia) or equal volume of vehicle by gavage for 8 days. The protein expression of p47PHOX subunit was assessed by Western Blot. Pancreatic islets of MSG animals showed an increase of 15% in protein expression of p47PHOX compared with the CTL group. However, treatment with losartan in the MSG group led to 30% of decrease in expression of this protein. Liver of animals MSG, showed a significant increase (p<0.01) of the p47PHOX content compared to CTL which was reversed after losartan reaching to CTL levels. Increased superoxide generation in pancreatic islets of MSG animals was blunted after losartan treatment.ConclusionWe conclude that losartan treatment reduces the expression of subunit p47 PHOX in both hepatic tissue and islets of MSG rats which may act as an important modulator of insulin resistance of this animals.