Biochemical analysis of caudate nucleus biopsy samples from parkinsonian patients.

Biochemical analyses of caudate nucleus biopsy samples from patients with Parkinson's disease undergoing autologous adrenal transplantation were performed. Activity of the dopamine biosynthetic enzyme tyrosine hydroxylase, and concentrations of dopamine and its primary metabolite homovanillic acid were significantly greater than anticipated on the basis of previously published postmortem values. These data suggest that postmortem changes in various biochemical parameters of dopamine function are more rapid than has been generally appreciated. Further analysis of striatal biopsy samples may reveal predictive relationships between striatal indices of dopamine function and therapeutic response to adrenal transplantation.