Release by tubocurarine of dopamine and homovanillic acid from the superfused caudate nucleus.

1. The release of dopamine and its metabolite homovanillic acid from the ;superfused' caudate nucleus was studied in the cat. Fluorimetric assay of the two compounds was carried out on 30 min samples of artificial cerebrospinal fluid perfused through the anterior horn of one lateral ventricle.2. When tubocurarine 0.5 or 1 x 10(-4) g/ml. was added to the perfusion fluid, amounts of dopamine of the order of 0.1 ng/min, and very much larger quantities of homovanillic acid (up to 8 ng/min) appeared in the perfusing fluid.3. No release of dopamine was obtained under conditions when tubocurarine failed to produce any clinical signs or when gallamine was substituted for tubocurarine.