[Hypoglycemic effects of peroxovanadate complexes on glucose transportor of diabetic rats].
OBJECTIVE
To demonstrate the hypoglycemic effects and translocation of glucose transport (Glut 1 and Glut 4) promoted by peroxovanadate and nicotinic acid complexes (POR) in streptozotozin-induced diabetic rats.


METHODS
Peroxovanadate complexes nicotinic acid (POR) was prepared in laboratory. POR and vanadate were administered in drink water. The muscles from diabetic rats were subjected to sucrose density gradient centrifugation to prepare plasma membrane and microsome membrane. Antibodies to COOH-terminal of glucose transportor were used in Western Blot to evaluate the translocation.


RESULTS
Peroxovanadate complexes of nicotinic acid (POR) showed marked hypoglycemic effects on STZ-induced diabetic rats. 1mg/kg oral pathway POR could significantly reduce the plasma glucose levels (from 18.95 +/- 2.61mmol/L to 6.36 +/- 2.23mmol/L, t = 12.233, P < 0.01) over four week's treatment, whereas, same dose of single sodium vanadate or nicotinic acid did not have hypoglycemic effects. The net vanadium intake was about 1/90 of single effectively vanadate treatment. When Western blot was used POR increased the translocation of Glut 4 and Glut 1 from intracellular site of plasma membrane.


CONCLUSIONS
Peroxovanadate-nicotinic acid complexes (POR) are the novel vanadyl that markedly reduce plasma glucose in a lower dose comparing to vanadate in STZ-DM rats by oral administration. Translocation of glucose transportor may play a part in hypoglycemic mechanism.
Yuan
M
M
Research Unit of Endocrinology, First University Hospital, Sun Yat-sen University of Medical Sciences, Guangzhou.
Yu
B
B
Liang
Y
Y
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009539:Nicotinic Acids / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014638:Vanadates / Q000494:pharmacology*
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D009539:Nicotinic Acids; C069276:peroxovanadate; D014638:Vanadates; D005947:Glucose