Zinc-deficient rats are insensitive to glucoprivation caused by 2-deoxy-D-glucose

Three-choice macronutrient intake studies indicate that zinc-deficient (Zn-) rats selectively decrease intake of carbohydrate. Because glucoprivic stimuli increase food intake and selection for carbohydrate, the ability of Zn- rats to respond to glucoprivation induced by 2-deoxy-D-glucose (2-DG) was tested. Rats were fed a Zn-adequate (Zn+) or Zn- diet. In part 1, rats were challenged with 0, 250, or 400 mg 2-DG/kg BW (i.p.) after zinc deficiency was established. In part 2, rats received saline or 2-DG while zinc deficiency was being induced and then after deficiency was established. Food intake was increased after injection of 2-DG to Zn+ rats; however, food intake was not higher after 2-DG administration to Zn- rats. A dose-response test for 2-DG further confirmed these results. In part 2, it was found that Zn- rats lose the response to 2-DG administration when zinc deficiency-induced anorexia begins, after 3 days of consuming a zinc-deficient diet. It appears that the ability to sense blood glucose concentrations may be impaired during zinc deficiency, and this impairment could be a part of the anorexia that develops during zinc deficiency in the rat.