DEFICIENCY OF SELENIUM ENHANCES THE K-INDUCED RELEASE OF DOPAMINE IN THE STRIATUM OF MICE()

To determine whether a selenium (Se) deficiency in the brain leads to a functional change in dopaminergic transmission in the striatum, in v ivo microdialysis was conducted in mice fed a low-Se diet. After 11-13 weeks of the diet regimen, the activity of glutathione peroxidase (GP x) in the Se-deficient brain was reduced to 60% of the control brain. A high K+ perfusion (100 mM) increased the level of dopamine in the di alysate to 67 +/- 16 times the basal level; the increase was significa ntly greater than that observed in the control group (28 +/- 4 times). Such a between-group difference was not observed after 4-5 weeks of t he Se-diet. These results indicated that prolonged Se deficiency alter ed the function of striatal dopaminergic neurons in mice. A possible c ontribution of enhanced oxidative stress due to the reduced GPx activi ty is discussed. (C) 1997 Elsevier Science Ireland Ltd.