NIGRAL DOPAMINERGIC CELL LOSS IN VITAMIN-E-DEFICIENT RATS

alpha-TOCOPHEROL concentrations in brain were reduced to 3% of control levels in rats fed a vitamin E deficient diet for 52 weeks. Vitamin E deficiency resulted in a 19-33% loss of tyrosine hydroxylase (TH) imm unopositive neurones in the substantia nigra, but not in the adjacent ventral tegmental area, compared with controls. Vitamin E deficiency, however, did not reduce striatal dopamine concentrations or turnover. When antioxidant defence mechanisms are defective, as in chronic vitam in E deficiency, the nigrostriatal pathway may be affected by oxidativ e damage and this may have implications for Parkinson's disease.