INCREASED POTENCY OF VANADIUM USING ORGANIC-LIGANDS

The in vivo glucose lowering effect of orally administered inorganic v anadium compounds in diabetes was first reported in our laboratory in 1985. While both vanadate and vanadyl forms of vanadium are orally act ive, they are still not well absorbed. We have synthesized several org anic vanadium compounds and one compound, bis(maltolato)oxovanadium(lv ) or BMOV, has been extensively investigated. BMOV proved effective in lowering plasma glucose and lipids in STZ-diabetic: rats when adminis tered in drinking water over a 25 week period. The maintenance dose (0 .18 mmol/kg/day) was approximately 50% of that required for vanadyl su lfate (VS). Secondary complications of diabetes were prevented by BMOV and no marked toxicity was noted. Oral gavage of STZ-diabetic rats wi th BMOV also reduced blood glucose levels. The ED(50) for BMOV was 0.5 mmol/kg, while for VS the estimated ED(50) was 0.9 mmol/kg. BMOV was also effective by the intraperitoneal route in STZ-diabetic rats. The ED(50) was 0.08 mmol/kg compared to 0.22 mmol/kg for VS. Some animals treated p.o. or i.p. remained euglycemic for up to 14 weeks. An i.v. i nfusion of BMOV of 0.05 mmol/kg over a 30 min period reduced plasma gl ucose levels by 50% while VS was not effective.