Does endogenous prostaglandin affect gastric antral motility?

Intracellular electrical activity and muscle contraction were recorded simultaneously from circular muscle of the canine antrum. Treatment with indomethacin enhance the plateau phase of the spontaneously occurring gastric action potential and the amplitude of the phasic contraction. Exogenous PGE₂ reversed this effect of indomethacin. Treatment with indomethacin also enhanced the electrical and mechanical responses to pentagastrin; this enhancement was also reversed by PGE₂. Considered together, these results suggest that endogenous prostaglandin, probably of the E series, tonically suppresses the spontaneous electrical and mechanical activities of antral circular muscle and the responsiveness of the muscle to excitatory stimuli.