A biochemical study of cholinergic-dopaminergic interactions in the central nervous system

The effects of cholinergic (Ach) and anti-Ach drugs on striatal dopamine (DA) levels and turnover were studied. Treatment with both atropine sulfate and scopolamine hydrobromide increased striatal DA levels; scopolamine increased striatal DA turnover and decreased both striatal 3,4-dihydroxyphenylacetic acid (DOPAC) levels and DOPAC/homovanillic acid (HVA) relation. Oxotremorine decreased striatal DA levels but did not change striatal DA turnover or DA metabolites. Changes in striatal DA levels or turnover were not observed after atropine methyl nitrate or physostigmine. The data show the Ach-DA interactions in the striatum.