Abstract
Underground water in Mt. Fuji area is enriched with vanadium, and drinking water contains vanadium with concentrations varying between 0.06 and 0.10 mg/L . In cultured cells, vanadium has been reported to activate insulin-receptors and facilitate the utilization of glucose. Therefore, anti-diabetic effect of vanadium is widely expected. However, the effect of vanadium at concentration of tap water level (VTL) to decrease blood glucose has not yet been confirmed in animal experiments, and thus its physiological action remains unclear. To examine whether VTL affects the taste sense, we compared taste thresholds to glucose, proline, and hydrogen chloride. Participants were healthy college students without a habit of smoking. They were requested to report recognition threshold of these substances after they tested them with and without vanadium in distilled water at least 2 h after their breakfast or lunch. Coexistence of 0.1 mg/L vanadium decreased threshold concentration of glucose by 25%. Sweet taste threshold to proline was not affected by vanadium at 0.1 mg/L but decreased by 1.0 mg/L vanadium. Sour taste threshold to hydrogen chloride was not affected by vanadium either at 0.1 mg/L or 1.0 mg/L. Sweet taste threshold to glucose was influenced by VTL rather specifically. We have identified one of the physiological roles of VTL. It is possible that vanadium facilitates a mechanism which sensitizes taste cells responding to glucose. [Jpn J Physiol 54 Suppl:S242 (2004)]
