Attempt to prevent the development of diabetes in non-obese diabetic mice by oral vanadate administration

Background: Despite current treatment protocols, the long-term complication s of insulin-dependent diabetes mellitus have prompted the investigation of strategies for the prevention of IDDM. Objectives: To investigate the effect of oral vanadate in reducing diabetes type I in non-obese diabetic mice. Methods: Sodium metavanadate, 3.92 mmol/L, was added to the drinking water of 8-week-old female NOD mice. Blood glucose levels, water consumption and body weight were measured, and the end point of the study was judged by the appearance of hyperglycemia in the mice. Results: Treatment with vanadate did not significantly reduce the incidence of type I diabetes as compared to the control group. However, oral vanadat e therapy significantly reduced the blood glucose levels after the fourth w eek of treatment compared to the control group (3.83+/-0.67 vs. 4.44+/-0.83 mmol/L, P<0.03). There was a consistent and significant increase in body w eight of the vanadate-treated pre-diabetic NOD mice compared to the control s. Diabetic mice treated with vanadate had significantly lower levels of se rum insulin as compared to control diabetic mice (104+/-27 vs. 151+/-36 mu mol/L, P<0.03). Histologically, no significant differences were found in in flammatory response of the islets of Langerhans between the control and tre ated groups. Conclusions: This study suggests that the postreceptor insulin-like effect induced by vanadate is not sufficient to prevent the development of diabete s and insulitis in pre-diabetic NOD mice.