Interleukin (IL)-1 beta, IL-6, epidermal growth factor (EGF), and transforming growth factor-alpha (TGF-alpha) were measured for the first time in the brain (caudate nucleus, putamen and cerebral cortex) from control and parkinsonian patients by highly sensitive sandwich enzyme immunoassays. The concentrations of IL-1 beta, IL-6, EGF, and TGF-alpha in the dopaminergic, striatal regions were significantly higher in parkinsonian patients than those in controls, whereas those in the cerebral cortex did not show significant differences between parkinsonian and control subjects. Since these cytokines and growth factors may play important roles as neurotrophic factors in the brain, the present results suggest that they may be produced as compensatory responses in the nigrostriatal dopaminergic regions in Parkinson's disease, and may be related, at least in part, to the process of neurodegeneration in Parkinson's disease.