Suppressive effects of intraventricular injected dopamine and nomifensine on muricide induced by thiamine deficiency.

The effects of dopamine (DA) and nomifensine (NF) on muricide activity induced by thiamine deficiency were examined. The chronic administration of L-dopa and nomifensine during feeding of thiamine deficient diet attenuated the muricide activity. Moreover, acute administration of L-dopa or nomifensine (IP) and dopamine or nomifensine (ICV) suppressed the thiamine deficiency-induced muricide activity dose-dependently. Small doses of apomorphine inhibited the muricide response significantly. The suppressive effects of dopamine and nomifensine were antagonized by pretreatment with 6-hydroxydopamine, but were not changed by pretreatment with p-chlorophenylalanine. These results suggest that the dopaminergic system has an important role in the regulation to the thiamine deficiency-induced muricide response.