DAILY ZINC SUPPLEMENTATION EFFECT ON ZINC-DEFICIENCY IN RATS DURING PROLONGED RESTRICTION OF MOTOR-ACTIVITY

The objective of this investigation was to evaluate the effect of 47 m g zinc supplementation on deficiency of zinc in rats during 98 d of re striction of motor activity (hypokinesia), which appeared by higher pl asma zinc concentration.One Hundred 13-week-old Sprague-Dawley male ra ts weighing 360-390 g were used to perform the studies: They were equa lly divided into four groups: 1. Unsupplemented control animals (UCA); 2. Unsupplemented hypokinetic animals (UHA); 3. Supplemented control animals (SCA); and 4. Supplemented hypokinetic animals (SHA). For the simulation of the effect of hypokinesia (HK), the UHA and SHA were kep t in small individual cages made of wood, which restricted their movem ents in all directions without hindering food and water intake. The SC A and SHA received daily with their food an additional amount of zinc. Before and during the experimental period of 98 d, plasma, urinary an d fecal zinc, balance of zinc, food intake, and body weight were deter mined at different intervals. In the SHA and UHA, the concentration of zinc in plasma, and the elimination of zinc in urine and feces increa sed significantly when compared with the SCA and UCA, whereas the bala nce of zinc was negative. The body weight and food intake decreased si gnificantly in the SHA and UHA when compared with the SCA and UCA. The increased plasma concentration of zinc in both the SHA anti UHA group s was in contrast to the observed hypozincnemia during prolonged immob ilization as during prolonged hospitalization. This reaction suggests that there may be some other mechanisms that are affecting the process of control and regulation of zinc metabolism during prolonged HK. It was concluded that exposure to prolonged restriction of motor activity of rats induces significant increases in plasma concentration, fecal and urinary elimination of zinc in the presence of negative zinc balan ce and regardless the daily intake of large amounts of zinc with their food, leading to zinc deficiency.