Orally active and long-term acting insulin-mimetic vanadyl complex:bis(picolinato)oxovanadium (IV).

The blood glucose level of rats with streptozotocin (STZ)-induced diabetes has been found to be normalized by administration of vanadyl or vanadate complexes. During our investigations on the development of anti-diabetic vanadyl complexes with various types of coordination mode such as V-O, V-N and V-S, we found that a new bis(picolinato)oxovanadium (IV) complex (VPA) has a strong insulin-mimetic effects as evaluated by an in vitro experiments, in which the inhibition of free fatty acid release in isolated rat adipocytes treated with epinephrine was observed to be similar to that of insulin. VPA was also effective for normalizing the blood glucose level of STZ-induced diabetic rats when given intraperitoneally or orally. The serum glucose level was maintained in the normal range for about 30 days with body weight gain after the end of oral administration of VPA for 14 days. VPA was confirmed to be an orally active and long-term acting insulin-mimetic vanadyl complex to treat insulin-dependent diabetes mellitus (IDDM) in rats.