LONG-TERM CORRECTION OF STZ-DIABETIC RATS AFTER SHORT-TERM IP VOSO4 TREATMENT - PERSISTENCE OF INSULIN-SECRETING CAPACITIES ASSESSED BY ISOLATED PANCREAS STUDIES

We have previously shown that 3 week oral VOSO4 treatment of streptozo tocin (STZ, 60 mg/kg)-induced diabetic rats was able to correct diabet es for 13 weeks after treatment withdrawal. In the present study, we i nvestigated whether a short-term (8 days) i.p. VOSO4 treatment was sim ilarly able to reverse the diabetic state. Insulin secretory capacitie s were assessed at distance of treatment using the isolated pancreas p reparation. Seven treatment-groups were performed: high dose VOSO4-tre ated diabetics (HVD, 1.3 mM/kg/8 days), food-restricted diabetics (FRD , food adjusted to HVD levels), low dose VOSO4-treated diabetes (LVD, 0.06 mM/kg/day), insulin-treated diabetics (ID, dose adjusted to norma lize glycaemia) and VOSO4 (0.06 mM/kg/day) + insulin (dose adjusted to normalize glycaemia in the presence of vanadium)-treated diabetics (I VD), in addition to the corresponding untreated non-diabetic controls (C) and diabetics (D). Our results indicate that long-term correction of diabetes (a) can be obtained after an 8 day treatment using i.p. VO SO4 in diabetic animals retaining some degree of pancreatic function, (b) is not obtained with insulin treatment or food restriction althoug h the association of VOSO4 and insulin was found beneficial, (c) can b e prolonged in some individuals for at least 4 months, i.e. in conditi ons such that tissue vanadium concentrations had returned to values cl ose to pre-treatment levels, (d) is associated with improved and in so me cases normalized insulin secretion from isolated pancreas. The prot ective or corrective role of VOSO4 on diabetes-related pancreatic alte rations, as well as the potential of the VOSO4-insulin association sho uld be further studied in view of the possible use of vanadium derivat ives in the treatment of diabetes.