Effects of zinc deficiency on ethanol metabolism and alcohol and aldehyde dehydrogenase activities

Alcohol dehydrogenase, low Km and high Km mitochondrial and microsomal aldehyde dehydrogenase, and in vivo ethanol elimination rates were determined in five groups of male Sprague-Dawley rats given liquid diets, as follows: control (C), control plus 5% ethanol (CE), pair-fed control and zinc-deficient (PC-ZnD), zinc-deficient (ZnD), and zinc-deficient plus 5% ethanol (ZnDE). Rats fed CE had decreased liver and serum zinc content. The animals given ZnD diets had an even more dramatic decrease in their tissue zinc concentrations and displayed marked growth retardation. The in vivo blood ethanol elimination rate was increased in animals fed ethanol, and this increase was accompanied by increased alcohol and aldehyde dehydrogenase activities. There was a significant decrease in the ethanol elimination rate in rats given ZnD and ZnDE diets. Alcohol dehydrogenase activities in rats with deficient zinc levels also were decreased, and there were no changes in acetaldehyde dehydrogenase activities. Our results suggest that the metabolism of ethanol to acetaldehyde is impaired in zinc deficiency, but acetaldehyde to acetate conversion appears normal.