Brichard S M, Pottier A M, Henquin J C
Unité de Diabétologie et Nutrition, University of Louvain, Faculty of Medicine, Brussels, Belgium.
Endocrinology. 1989 Nov;125(5):2510-6. doi: 10.1210/endo-125-5-2510.
The trace element vanadium (V) exerts insulin-like effects in vitro and lowers blood glucose in streptozotocin-diabetic rats. The present study examined whether V can also improve glucose homeostasis in genetically obese, insulin-resistant rats. Na3VO4 was administered for 3 months in water and food to Zucker fa/fa rats. Since these V rats reduced their food intake by about 30% compared to controls (C), one group of untreated rats was pair-fed (P-F) with V rats. In the fed state, the insulin/glucose ratio was lower in V rats than in P-F or C rats, merely because of a decrease (approximately 50%) in plasma insulin levels. Tolerance to oral glucose was improved in V rats only; the integrated glucose response was 30% lower than that in P-F or C rats. Insulin levels were also lower in V rats, but the integrated response was not consistently decreased. During an iv glucose tolerance test, the glucose disappearance rate was 50% higher in V rats than in the other two groups. An iv arginine test clearly showed that B-cell responsiveness was not increased in V rats. Insulin sensitivity, assessed by insulin-induced hypoglycemia, was similar in V and P-F rats and slightly better than that in C rats. In conclusion, oral vanadate produces a sustained improvement of glucose homeostasis by an insulin-like, largely body weight-independent mechanism in genetically insulin-resistant rats.
微量元素钒（V）在体外具有胰岛素样作用，并能降低链脲佐菌素诱导的糖尿病大鼠的血糖。本研究检测了钒是否也能改善遗传性肥胖、胰岛素抵抗大鼠的葡萄糖稳态。将Na3VO4添加到饮水中和食物中，对Zucker fa/fa大鼠给药3个月。由于与对照组（C）相比，这些钒处理的大鼠食物摄入量减少了约30%，因此一组未处理的大鼠与钒处理的大鼠进行配对喂养（P-F）。在进食状态下，钒处理的大鼠胰岛素/葡萄糖比值低于配对喂养组或对照组大鼠，这仅仅是由于血浆胰岛素水平降低（约50%）所致。只有钒处理的大鼠口服葡萄糖耐量得到改善；葡萄糖综合反应比配对喂养组或对照组大鼠低30%。钒处理的大鼠胰岛素水平也较低，但综合反应并未持续降低。在静脉注射葡萄糖耐量试验中，钒处理的大鼠葡萄糖消失率比其他两组高50%。静脉注射精氨酸试验清楚地表明，钒处理的大鼠B细胞反应性并未增加。通过胰岛素诱导的低血糖评估的胰岛素敏感性，在钒处理的大鼠和配对喂养的大鼠中相似，且略优于对照组大鼠。总之，口服钒酸盐通过一种胰岛素样的、很大程度上与体重无关的机制，使遗传性胰岛素抵抗大鼠的葡萄糖稳态得到持续改善。
