Insulin mimetic effect of a tungstate cluster. Effect of oral administration of homo-polyoxotungstates and vanadium-substituted polyoxotungstates on blood glucose level of STZ mice

Citation
K. Nomiya et al., Insulin mimetic effect of a tungstate cluster. Effect of oral administration of homo-polyoxotungstates and vanadium-substituted polyoxotungstates on blood glucose level of STZ mice, J INORG BIO, 86(4), 2001, pp. 657-667
Citations number
52
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics","Inorganic & Nuclear Chemistry
Journal title
JOURNAL OF INORGANIC BIOCHEMISTRY
ISSN journal
0162-0134 → ACNP
Volume
86
Issue
4
Year of publication
2001
Pages
657 - 667
Database
ISI
SICI code
0162-0134(200110)86:4<657:IMEOAT>2.0.ZU;2-Y
Abstract
Aqueous vanadate and aqueous tungstate have been known to mimic all or most of the actions of insulin in intact cell systems with respect to normaliza tion of the blood glucose level. By carrying out oral administration in viv o experiments on the blood glucose level of streptozotocin (STZ)-induced di abetes (STZ mice), the insulin-mimetic (IM) effects of metal-oxide clusters of all-inorganic composition were examined using many types of polyoxometa lates (POM) with and without vanadium substitution. Several homo-POM and va nadium-substituted POM showed hypoglycemic effects. The observed hypoglycem ic effects indicated that POM with the Dawson structure ([alpha -P2W18O62]( 6-) (W-2), [alpha -(P2W17VO62)-O-v](7-) (V-19) and [alpha -1,2,3-(P2W15VO62 )-O-v](9-) (V-04)) are more effective than those with the Keggin structure ([alpha -P2W12O40](6-) (W-1), [alpha -(PW11VO40)-O-v](4-) (V-01), [alpha -1 ,2-(PW10V2O40)-O-v](5-) (V-02), [alpha -1,2,3-(PW9V3O40)-O-v](6-) (V-03) an d [alpha -1,4,9-(PW9V3O40)-O-v](6-) (V-13)). The vanadate cluster [VtoO28]( 6-) (V-15) also showed a hypoglycemic effect. P-31 and V-51 NMR 3 measureme nts showed that the Dawson POM (W-2, V-04 and V-19) are stable in aqueous s olution under the conditions used. The effect of all POM on the body weight of STZ mice was also examined. The decrease in body weight after administr ation of W-2 was much less than for V-19, V-04 and V-15, This suggests that not only monomeric tungstate and vanadate, but also the structure factors of tungstate and vanadate clusters, can play a significant role in their bi ological action. (C) 2001 Elsevier Science BY. All rights reserved.