Insulin-Mimetic Action of Vanadate: Role of Intracellular Magnesium

• Published in: Hypertension (Dallas, Tex. 1979) Tex. 1979), 2001-09, Vol.38 (3, Part 2 Suppl), p.701-704
• Main Authors: Barbagallo, Mario, Dominguez, Ligia J, Resnick, Lawrence M
• Format: Article
• Language: English
• Subjects: Apud cells. Peptide and protein hormones. Growth factors; Biological and medical sciences; Dose-Response Relationship, Drug; Erythrocytes - cytology; Erythrocytes - drug effects; Erythrocytes - metabolism; Female; Fundamental and applied biological sciences. Psychology; Humans; Hypertension - blood; Insulin - pharmacology; Magnesium - blood; Magnetic Resonance Spectroscopy; Male; Time Factors; Vanadates - pharmacology; Vertebrates: endocrinology
• ISSN: 0194-911X; 1524-4563
• DOI: 10.1161/hy09t1.095392

The insulin-mimetic effect of vanadate is well established, and vanadate has been shown to improve insulin sensitivity in diabetic rats and humans. Although the exact mechanism(s) remain undefined, we have previously demonstrated a direct relation of intracellular free magnesium (Mgi) levels to glucose disposal, to insulinemic responses following glucose loading, and to insulin-induced ionic effects. To investigate whether the insulin-mimetic effects of vanadate could similarly be mediated by Mgi, we utilized P-nuclear magnetic resonance spectroscopy to measure Mgi in erythrocytes from normal (NL, n=10) and hypertensive (HTN, n=12) subjects, before and after incubation with insulin and with different doses of sodium vanadate. In NL, vanadate elevated Mgi levels, with maximum efficacy at 50 7mgr;mol/L (186±6 to 222±6 7mgr;mol/L, P >0.01), as did physiologically maximal doses of insulin, 200 7mgr;U/mL (185±6 to 222±8 7mgr;mol/L, P