Dietary zinc-deficiency and its recovery responses in rat liver cytosolic alcohol dehydrogenase activities

The purpose of the present study was to elucidate the effects of dietary zinc-deficient feeding and its recovery on liver cytosolic alcohol dehydrogenase (ADH; alcohol: NAD+ oxidoreductase, EC1.1.1.1) activities and plasma zinc levels in rats. The weaned male Sprague Dawley rats were randomly divided into the zinc-deficient diet (ZDF: 1.9 mg zinc/kg diet) group and the control diet (53.5 mg zinc/kg diet) group, and were fed for 4 weeks. In the recovery periods, the rats of two groups were fed with the control diet for 3 weeks. Liver cytosolic protein content per body weight in the zinc-deficiency and its recovery period showed no significant changes between both groups. However, zinc-deficiency decreased significantly liver cytosolic ADH specific activity, total liver cytosolic ADH activity and total liver cytosolic ADH activity/body weight by 50%, 76% and 53%, respectively, as compared with the control diet group. Zinc-deficiency also decreased significantly plasma zinc concentration by 84%, as compared with the control diet group. On the contrary, no significant changes in liver cytosolic ADH specific activity, total liver cytosolic ADH activity and total liver cytosolic ADH activity/body weight in the recovery period were observed between both groups. Plasma zinc concentration in the recovery period was almost recovered to the control level. These results suggest that rat liver cytosolic ADH activity was clearly related to dietary zinc intake levels.