Mucin Secretion Evoked by Prostaglandin E2 in Guinea Pig Antral Mucous Cells: Role of EP1/EP4 Receptors

Abstract

Effects of prostaglandin E2 (PGE2) on exocytosis in antral mucous cells isolated from guinea pigs were studied using video-microscopy. Stimulation with PGE2 evoked a sustained increase in the frequency of exocytotic events, which was under regulation by both Ca2+ and cyclic adenosine monophosphate (cAMP) signals. An EP1 agonist (17-P-T-PGE2) activated the Ca2+ signals and evoked only small increases in the frequency of exocytotic events, increasing the sensitivity of exocytosis to the cAMP signal. An EP4 agonist (ONO-AE1–329), which activated the cAMP signals and elicited a sustained increase in the frequency of exocytotic events, potentiated the frequency of exocytotic events regulated by the Ca2+ signals by increasing the sensitivity to the Ca2+. In conclusion, PGE2-evoked exocytotic events in antral mucous cells were regulated by interactions between EP1 and EP4 receptors.