[Hypoglycemic effects of sodium metavanadate in diabetic mice and its effect on glucose phosphorylation].

ABSTRACT

OBJECTIVE: To investigate the effects of sodium metavanadate (SMV) on blood sugar and glucose phosphorylation in mice, and to discuss the possible mechanism of its hypoglycemic effects. METHODS: Diabetic mice (D) and control mice (V) were randomly allocated to drink SMV (0.2 mg/ml) (CV and DV groups) or NaCl (80 mmol/L) (C and V groups) respectively. The study lasted for 5 weeks. Liver glucokinase, muscle hexokinase, blood glucose and insulin were assayed at the end of each week. RESULTS: Blood glucose was higher in the diabetic groups before the administration of SMV, and the blood glucose level of group DV decreased from (18.77 +/- 1.28) to (8.94 +/- 0.94) mmol/L (P < 0.01) after oral administration of SMV for one week. While liver glucokinase increased from (1.29 +/- 0.64) to (15.36 +/- 1.57) mIU/min/mg protein and muscle hexokinase increased from (1.93 +/- 0.50) to (18.62 +/- 1.71) mIU/min/mg protein (P < 0.01) respectively. There was no continuous change of these parameters during the later weeks. No significant change of serum insulin was observed in the diabetic mice. There was a remarkable negative correlation of blood glucose level with liver glucokinase and muscle hexokinase levels. CONCLUSION: The hypoglycemic effects of SMV was independent of insulin level. In consideration of the close relations of the activities of liver glucokinase and muscle hexokinase with diabetes, and the improving of impaired glucose phosphorylation in diabetic mice by oral sodium metavanadate, which might be the mechanism of hypoglycemic effects of SMV.