Striffler J S, Polansky M M, Anderson R A
Nutrient Requirements and Functions Laboratory, Beltsville Human Nutrition Research Center, MD 20705-2350, USA.
Metabolism. 1998 Apr;47(4):396-400. doi: 10.1016/s0026-0495(98)90049-x.
The effects of chromium (Cr) supplementation on diet-induced insulin resistance produced by feeding a high-fat, low-Cr diet were studied in rats to ascertain the role of Cr in insulin resistance. Wistar male rats were maintained for 16 weeks after weaning on a basal diet containing 40% lard, 30% sucrose, and 25% casein by weight and adequate vitamins and minerals without added Cr (-Cr). Fasting levels of insulin, glucose, and triglycerides and the responses during an intravenous glucose tolerance test (IVGTT) were compared as indices of insulin resistance and the effectiveness of dietary Cr. IVGTTs and blood sampling for data analyses were performed over a 40-minute period after IV glucose injection (1.25 g/kg body weight) in overnight-fasted animals under pentobarbital anesthesia (40 mg/kg body weight). All animals were normoglycemic (-Cr, 109 +/- 3 mg/dL; +Cr, 119 +/- 5), with fasting insulin levels elevated in the -Cr group (65 +/- 10 microU/mL) versus the +Cr group (31 +/- 4 microU/mL). Increases in plasma triglycerides in the -Cr group were not significant. Following glucose injection, the rate of glucose clearance was lower in the -Cr group (1.74 +/- 0.22 v2.39 +/- 0.11%/min), and 40-minute glucose areas in the -Cr group tended to be higher than in the +Cr group. The insulin response to glucose injection was 20% higher in the -Cr group. Forty-minute plasma triglyceride areas were lower in +Cr rats (875 +/- 62 v 1,143 +/- 97 mg/dL.min in -Cr rats). These data demonstrate that the insulin resistance induced by feeding a high-fat, nutrient-stressed diet is improved by Cr.
研究了补充铬（Cr）对高脂、低铬饮食诱导的大鼠饮食性胰岛素抵抗的影响，以确定铬在胰岛素抵抗中的作用。将Wistar雄性大鼠断奶后，在基础饮食上维持16周，该基础饮食按重量计含有40%猪油、30%蔗糖和25%酪蛋白，并含有充足的维生素和矿物质，但未添加铬（-Cr）。比较空腹胰岛素、葡萄糖和甘油三酯水平以及静脉葡萄糖耐量试验（IVGTT）期间的反应，作为胰岛素抵抗和膳食铬有效性的指标。在戊巴比妥麻醉（40mg/kg体重）下，对过夜禁食的动物静脉注射葡萄糖（1.25g/kg体重）后40分钟内进行IVGTT和采血以进行数据分析。所有动物血糖正常（-Cr组，109±3mg/dL；+Cr组，119±5），-Cr组空腹胰岛素水平（65±10μU/mL）高于+Cr组（31±4μU/mL）。-Cr组血浆甘油三酯的升高不显著。注射葡萄糖后，-Cr组葡萄糖清除率较低（1.74±0.22对2.39±0.11%/分钟），-Cr组40分钟葡萄糖面积倾向于高于+Cr组。-Cr组对葡萄糖注射的胰岛素反应高20%。+Cr大鼠40分钟血浆甘油三酯面积较低（-Cr大鼠为875±62对1143±97mg/dL·分钟）。这些数据表明，高脂、营养应激饮食诱导的胰岛素抵抗可通过铬得到改善。
