Different Forms of Vanadate on Sugar Transport in Insulin Target and Nontarget Cells

Abstract

<p>The effects of several vanadates (ie, orthovanadate, pervanadate, and two stable peroxovanadium compounds) on basal and insulin-stimulated 2-DG transport in insulin target and nontarget cell lines are reported, herein. In nontarget cells, exposure to vanadates (<math alttext="$5 imes 10^{-6}$"> <mrow> <mn>5</mn> <mo>&times;</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>&minus;</mo> <mn>6</mn> </mrow> </msup> </mrow> </math> to <math alttext="$10^{-4}$"> <mrow> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>&minus;</mo> <mn>4</mn> </mrow> </msup> </mrow> </math> mol/L) resulted in 2-DG transport stimulatory responses similar to those observed in 2-DG transport post exposure to 667 nmol/L insulin alone, or insulin in combination with vanadates. In 3T3-L1 adipocytes and L6 myotubes, exposure to a vanadate compound or 67 nmol/L insulin, stimulated 2-DG transport dramatically. Again, this effect on stimulated transport was similar to 2-DG transport post-treatment with the effective vanadates in combination with insulin. While pervanadate or stable peroxovanadates stimulated 2-DG transport at <math alttext="$10^{-5}$"> <mrow> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>&minus;</mo> <mn>5</mn> </mrow> </msup> </mrow> </math> to <math alttext="$10^{-6}$"> <mrow> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>&minus;</mo> <mn>6</mn> </mrow> </msup> </mrow> </math> mol/L, orthovanadate up to <math alttext="$10^{-4}$"> <mrow> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>&minus;</mo> <mn>4</mn> </mrow> </msup> </mrow> </math> mol/L was not effective in stimulating 2-DG transport in any of the cell lines tested. The data indicate that the various peroxovanadates are clearly superior insulin mimetics while a more limited insulin mimesis is observed with orthovanadate over a wide variety of cell types.</p

Uptake and metabolic effects of insulin mimetic oxovanadium compounds in human erythrocytes

“…These anti-diabetic properties of vanadium compounds, which have been demonstrated by in vitro [5][6][7][8][9][10], in vivo [11,12] and clinical studies [2,13,14], have attracted much interest as potential therapeutic agents for Diabetes mellitus [11,[15][16][17][18]. They can be administered orally and have been shown to promote glucose uptake in animal models of type 1 and type 2 diabetes [13,19].…”

Effects of decavanadate and insulin enhancing vanadium compounds on glucose uptake in isolated rat adipocytes

“…As an inhibitor of tyrosine-phosphatases, vanadate is known to increase of the protein phosphorylation [3] which can enhance a number of metabolic actions of insulin. Since it displays insulin-enhancing activity through normalizing metabolic disorders associated with insulin deficiency, vanadium and vanadium compounds are considered for clinical use in diabetes treatment [2,3,8]. Applications of vanadium compounds for the treatment and prevention of type 2 diabetes mellitus (T2DM) have been ongoing for more than two decades [2].…”