Effect of hypoxia and exercise on the distribution of 65Zn in rat muscles

The aim of this study was to determine the influence of hypoxia and exercise in 65Zn distribution in various rat muscles. A total of 80 male wistar rats weighting 250 +/- 10 g were randomly separated into eight groups: four groups in air, two at rest, and the other two after exercise; four groups in hypoxia (3 days exposure), two at rest, and the other two after exercise. Two groups (n = 10) in air and two other groups under hypoxia were injected with 65Zn. The 65Zn uptake by blood, pH, and PaO2 decreased significantly during hypoxia. The Zn concentration increased significantly in serum, diaphragm, gastrocnemius, and heart Zn after exercise in air. After hypoxia, at res, Zn increased in serum and in diaphragm. After chronic hypoxia, at rest, radioactivity of 65Zn increased in heart, gastrocnemius, and bone, and it was similar in air condition after exercise with respect to rest. In both cases (air and hypoxia), the uptake of 65Zn by the tissues was higher at rest. After exercise in hypoxia, endogenous Zn decreased in heart and in diaphragm.