Pharmacological analysis of the effects of metoclopramide on the transmurally stimulated guinea-pig ileum.

The effects of metoclopramide (Mcp), a benzamide derivative, have been quantitatively analyzed on the responses of the isolated guinea-pig ileum to transmural stimulation. Mcp (0.03 microgram ml-1 upwards) increased these responses but this effect which was calcium-dependent was not concentration-dependent (up to 30 micrograms ml-1). Mcp antagonized the inhibitor effects of noradrenaline, dopamine, procaïne, adenosine triphosphate, bufexamac and hydrocortisone on the ileal responses, but not those of tetrodotoxin and verapamil.