Pharmacologic evaluation of dopaminergic receptor blockade by metoclopramide

The occurrence of adverse extrapyramidal effects following metoclopramide (MCP) therapy has been well documented in humans. In rats, MCP produced catalepsy and inhibited apomorphine-induced stereotypy, locomotor activity, and rotational behavior. MCP also accelerated dopamine turnover, potently stimulated prolactin release, and, at high concentrations, inhibited [3H]spiperone binding to striatal membranes. These behavioral and biochemical effects induced by MCP were similar to those observed with haloperidol. We conclude that MCP possesses most of the pharmacological properties of neuroleptic agents.