Selective N-methyl-D-aspartate (NMDA) antagonists increase gastric motility in the rat.

Systemic administration of selective NMDA antagonists, such as CPP, APH, ketamine and MK-801, increased spontaneous gastric motility of the rat in a dose-dependent manner, and they prevented the NMDA-evoked depression of gastric motility. On the other hand, a broad spectrum excitatory amino acid antagonist, kynurenate, DNQX and CNQX decreased spontaneous gastric motility. Under the action of hexamethonium or chlorisondamine, CPP and MK-801 had little effect upon gastric motility. After the treatment with atropine, the motor responses to NMDA, CPP and MK-801 were hardly observed. Similar results were obtained after vagotomy.