The papers in this volume comprise invited reviews as well as original research papers presented at the Vanadium Symposium held July 29-31, 1994.
Vanadium is a trace element and its compounds have been shown to exert a wide variety of insulin-like effects including the ability to lower hyperglycemia in several experimental models of diabetes mellitus. Because of the possibility that vanadium compounds may be able to serve as potential therapeutic agents for the treatment of diabetes, and possibly other diseases, this trace element has attracted the attention of biomedical researchers from a variety of fields. The Vanadium Symposium 1994 was therefore organized to facilitate exchange of ideas and increase interaction among researchers of different disciplines actively engaged in studying the biological actions of vanadium compounds.
The papers are written by leading vanadium researchers and are grouped into three main sections: the chemistry, biochemical and physiological aspects, and potential therapeutic use and toxic effects of vanadium compounds. A good source of information on vanadium chemistry and biology.

Klappentext

In vitro and animal studies show that vanadate and other Because most cellular components contain hydroxyl and/or vanadium compounds increase glucose transport activity and phosphate groups, vanadate reacts as shown in eq. 1, and 2 normalize glucose metabolism [1-5]. Furthermore, these with a variety of metabolites. For example, the reaction of insulin-mimetic compounds can be administered orally. Vana vanadate with the 2'-hydroxyl group of the cofactor NAD date enhances the phosphoprotein formation which is attrib generates an NADP analog, NADV (path b) [22]. NADV is uted to either the activation of protein kinases or inhibition an excellent cofactor for enzymes such as glucose-6-phos of protein phosphatases. Despite the interest in document phate dehydrogenase, 6-phosphogluconate dehydrogenase, ing the effects of vanadate on protein kinases, most reports and alcohol dehydrogenase [22]. The presence ofNADV have used indirect methods and studies with purified kinases could affect the levels of reducing equivalents in the cell, im show weak, if any, interaction of vanadate with kinases as portant in maintaining a normal glucose metabolism. This a group of enzymes (reviewed in Refs. [6-8]). Vanadate type of mechanism is distinct from the vanadate-induced interacts potently with phosphatases and the inhibition is NADH oxidation by plasma membranes [23]. Organic attributed to a five-coordinate vanadate complex which vanadates have been shown to substitute for organic phos mimics the transition state of the phosphate ester hydroly phates in many of the enzymes related to glucose metabolism sis reaction (reviewed in Refs. [7,9]).

Zusammenfassung
The papers in this volume comprise reviews and research papers presented at the Vanadium Symposium held in 1994. The papers are grouped into three main sections: the chemistry; biochemical and physiological aspects; and potential therapeutic use and toxic effects of vanadium compounds.

Inhalt
I: Chemistry.- The chemistry of peroxovanadium compounds relevant to insulin mimesis.- Vanadium chemistry and biochemistry of relevance for use of vanadium compounds as antidiabetic agents.- Peroxo heteroligand vanadates(V): Synthesis, spectra-structure relationships, and stability toward decomposition.- Chemically and photochemically initiated DNA cleavage by an insulin-mimetic bisperoxovanadium complex.- II: Biochemical and physiological studies.- Insulin-like actions of vanadate are mediated in an insulin-receptor-independent manner via non-receptor protein tyrosine kinases and protein phosphotyrosine phosphatases.- Peroxovanadium compounds: Biological actions and mechanism of insulin-mimesis.- Unique and selective mitogenic effects of vanadate on SV40-transformed cells.- Vanadium salts stimulate mitogen-activated protein (MAP) kinases and ribosomal S6 kinases.- Protective effect of vanadate on oxyradical-induced changes in isolated perfused heart.- In vivo effects of vanadate on hepatic glycogen metabolizing and lipogenic enzymes in insulin-dependent and insulin-resistant diabetic animals.- The relationship between insulin and vanadium metabolism in insulin target tissues.- Modulation of insulin action by vanadate: Evidence of a role for phosphotyrosine phosphatase activity to alter cellular signaling.- Reversal of defective G-proteins and adenylyl cyclase/cAMP signal transduction in diabetic rats by vanadyl sulphate therapy.- Effects of vanadate on the expression of genes involved in fuel homeostasis in animal models of Type I and Type II diabetes.- Decrease in protein tyrosine phosphatase activities in vanadate-treated obese Zucker (fa/fa) rat liver.- Evidence for selective effects of vanadium on adipose cell metabolism involving actions on cAMP-dependent proteinkinase.- The enhancement by pervanadate of tyrosine phosphorylation on prostatic proteins occurs through the inhibition of membrane-associated tyrosine phosphatases.- Contractile effects of vanadate on aorta rings from virgin and pregnant rats.- In vivo modulation of N-myristoyltransferase activity by orthovanadate.- Regulation and control of glucose overutilization in erythrocytes by vanadate.- In vitro and in vivo antineoplastic effects of ortrovanadate.- Membrane vanadium interaction: A toxicokinetic evaluation.- III: Potential use in therapy and toxicological studies.- Increased potency of vanadium using organic ligands.- In vivo effects of peroxovanadium compounds in BB rats.- Long-term antidiabetic activity of vanadyl after treatment withdrawal: Restoration of insulin secretion?.- Long-term correction of STZ-diabetic rats after short-term i.p. VOSO4 treatment: Persistence of insulin secreting capacities assessed by isolated pancreas studies.- Antihypertensive effects of vanadium compounds in hyperinsulinemic, hypertensive rats.- Vanadate induces normolipidemia and a reduction in the levels of hepatic iipogenic enzymes in obese Zucker rat.- In vivo and in vitro studies of vanadate in human and rodent diabetes mellitus.- Toxicology of vanadium compounds in diabetic rats: The action of chelating agents on vanadium accumulation.- Index to Volume 153.