The mode of reduction of vanadate(+V) to oxovanadium (+IV) by glutathione and cysteine

Legrum, Wolfgang

doi:10.1016/0300-483x(86)90016-8

Cited by 36 publications

(19 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…12–15,101. In our hands vanadate(V) (20 mM) and glutathione (200 mM) at pH 8.9 produced a green solution in agreement with the reports that vanadate is reduced to vanadium(IV) in the presence of glutathione 16,101. The solution of vanadate and glutathione yielded a similar UV-visible spectrum and EPR spectrum (data not shown) to the 2-mercaptoethanol complex.…”

Section: Resultssupporting

confidence: 91%

Is Vanadate Reduced by Thiols under Biological Conditions? Changing the Redox Potential of V(V)/V(IV) by Complexation in Aqueous Solution

et al. 2010

View full text Add to dashboard Cite

Although dogma states that vanadate is readily reduced by glutathione, cysteine and other thiols, there are several examples documenting that vanadium(V)-sulfur complexes can form and be observed. This conundrum has impacted life scientists for more than two decades. Investigation of this problem requires an understanding of both the complexes that form from vanadium(IV) and (V) and a representative thiol in aqueous solution. The reactions of vanadate and hydrated vanadyl cation with 2-mercaptoethanol have been investigated using multinuclear NMR, EPR and UV-vis spectroscopy. Vanadate forms a stable complex of 2:2 stoichiometry with 2-mercaptoethanol at neutral and alkaline pH. In contrast, vanadate can oxidize 2-mercaptoethanol; this process is favored at low pH and high solute concentrations. The complex that forms between aqueous vanadium(IV) and 2-mercaptoethanol has a 1:2 stoichiometry and can be observed at high pH and high 2-mercaptoethanol concentration. The solution structures have been deduced and speciation diagrams prepared. This work demonstrates that both vanadium(IV) and (V)-thiol complexes form and that redox chemistry also takes place. Whether reduction of vanadate takes place is governed by a combination of parameters: pH, solute-and vanadate-concentrations and the presence of other complexing ligands. Based on these results it is now possible to understand the distribution of vanadium in oxidation states (IV) and (V) in the presence of glutathione, cysteine and other thiols and begin to evaluate the forms of the vanadium compounds that exert a particular biological effect including the insulin-enhancing agents, anti-amoebic agents and interactions with vanadium binding proteins.

show abstract

Section: Resultssupporting

confidence: 91%

Is Vanadate Reduced by Thiols under Biological Conditions? Changing the Redox Potential of V(V)/V(IV) by Complexation in Aqueous Solution

et al. 2010

View full text Add to dashboard Cite

show abstract

“…It undergoes reduction to vanadyl (VO2+; +4 oxidation state) inside the cell. The process of vanadium reduction occurs, among other things, with the participation of glutathione, cysteine, NADH, NADPH and L-ascorbic acid (Macara et al 1980, Heinz et al 1982, Legrum 1986). In the investigations presented here a significant decrease in the L-ascorbic acid level was noted in the plasma of males.…”

Section: Discussionmentioning

confidence: 99%

Effect of chronic vanadium administration in drinking water to rats

1993

View full text Add to dashboard Cite

Two-month old Wistar rats of both sexes received, as sole drinking liquid, an aqueous solution of ammonium metavanadate (AMV) at a concentration of 0.01 or 0.05 mg V cm-3 (0.2 or 1.0 mM) for a period of 4 weeks. It was calculated that the animals took up doses of 1.5 and 5-6 mg V kg body weight-1 24 h-1, respectively. Food and AMV solution consumption in the experimental group was similar to food and water consumption in the control group. A statistically significant decrease of consumption of AMV solution at a concentration of 0.05 mg V cm-3 was noted only in males. Hematological examination demonstrated a decrease in the erythrocyte count, hemoglobin level and hematocrit index. This decrease in the erythrocyte count was associated with an increased percentage of reticulocytes in the peripheral blood of the animals drinking the solution with a higher vanadium content. Biochemical analyses demonstrated a decrease of L-ascorbic acid levels in the plasma and erythrocytes of animals drinking the AMV solutions. A distinct tendency for the malonyldialdehyde level to increase in the blood was also observed. Among the enzymes examined in the erythrocytes (catalase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase and delta-aminolevulinic acid dehydratase [ALA-D]) only ALA-D activity was depressed.

show abstract

“…On the other hand, it has recently been suggested that the vanadyl rather than the vanadate form may be more appropriate for chronic use in diabetic rats (Ramanadham et al 1989a). Vanadyl is less toxic than vanadate (Llobet & Domingo 1984), and the insulin-like effects of vanadium appear to coincide with the presence or formation in vivo of vanadyl from vanadate (Dubyak & Kleinzeller 1980;Shechter & Karlish 1980;Legrum 1986). During the period 1989-1990 the effectiveness of chronic vanadyl treatment in STZ-induced diabetic rats was evaluated in several investigations (Pederson et al 1989;Ramanadham et al 1989aRamanadham et al ,b & 1990.…”

Section: Discussionmentioning

confidence: 99%

Improvement of Glucose Homeostasis by Oral Vanadyl or Vanadate Treatment in Diabetic Rats is Accompanied by Negative Side Effects

Domingo

Gómez

Llobet

et al. 1991

Pharmacology & Toxicology

View full text Add to dashboard Cite

Vanadate and vanadyl, two forms of vanadium, have been reported to exert insulin-like effects in vivo and in vitro. In the present study we compared the effectiveness of oral sodium metavanadate (NaVO3), sodium orthovanadate (Na3VO4) and vanadyl sulphate pentahydrate (VOSO4.5H2O) treatment in alleviating some signs of diabetes in streptozotocin-induced diabetic rats. Vanadium compounds were administered in aqueous solutions of NaCl (80 mM) at concentrations of 0.20 mg/ml (NaVO3), 0.50 mg/ml (Na3VO4), and 1.1 mg/ml (VOSO4.5H2O) for two weeks. Control rats, either diabetic or non-diabetic, drank solutions of NaCl (80 mM). Although some signs of diabetes (hyperglycaemia, hyperphagia, polydipsia) were significantly ameliorated by the vanadium treatment, negative side effects were also observed in all of the vanadium-treated diabetic rats. Those effects included some deaths, decreased weight gain, and tissue vanadium accumulation, which are consistent with the reported toxicity of vanadium in non-diabetic rats. Vanadyl sulphate was the most effective compound of those tested in normalizing blood glucose levels. However, the results here reported suggest that chronic administration of vanadyl or vanadate in the drinking water is not a viable alternative treatment to insulin in human diabetes.

show abstract

The mode of reduction of vanadate(+V) to oxovanadium (+IV) by glutathione and cysteine

Cited by 36 publications

References 15 publications

Is Vanadate Reduced by Thiols under Biological Conditions? Changing the Redox Potential of V(V)/V(IV) by Complexation in Aqueous Solution

Is Vanadate Reduced by Thiols under Biological Conditions? Changing the Redox Potential of V(V)/V(IV) by Complexation in Aqueous Solution

Effect of chronic vanadium administration in drinking water to rats

Improvement of Glucose Homeostasis by Oral Vanadyl or Vanadate Treatment in Diabetic Rats is Accompanied by Negative Side Effects

Contact Info

Product

Resources

About