The aim of this study was to determine the influence of hypoxia and ex
ercise in Zn-65 distribution in various rat muscles. A total of 80 mal
e wistar rats weighing 250 +/- 10 g were randomly separated into eight
groups: four groups in air, two at rest, and the other two after exer
cise; four groups in hypoxia (3 days exposure), two at rest, and the o
ther two after exercise. Two groups (n = 10) in air and two other grou
ps under hypoxia were injected with Zn-65. The Zn-65 uptake by blood,
pH, and PaO2 decreased significantly during hypoxia. The Zn concentrat
ion increased significantly in serum, diaphragm, gastrocnemius, and he
art Zn after exercise in air. After hypoxia, at rest, Zn increased in
serum and in diaphragm. After chronic hypoxia, at rest, radioactivity
of Zn-65 increased in heart, gastrocnemius, and bone, and it was simil
ar in air condition after exercise with respect to rest. In both cases
(air and hypoxia), the uptake of Zn-65 by the tissues was higher at r
est. After exercise in hypoxia, endogenous Zn decreased in heart and i
n diaphragm.