Uptake and turnover of(65)Zn in subcellular fractions of brain of rat under normal and zinc-deficient conditions.

After a single injection,(65)Zn is slowly taken up by the brain of the rat to a maximum after 7 d, followed by a turnover phase, with a half-time of about 3 wk. In the brain of rats on a zinc-deficient diet, the(65)Zn content in the brain continued to increase up to 30 d after the injection.The uptake and turnover phases in six different subcellular fractions of the brain showed a pattern similar to that of the whole brain in both the control and zinc-deficient rats. There was no internal redistribution of(65)Zn in the brain under conditions of progressive zinc deficiency.The results are discussed in a model for zinc homeostasis in the brain.