What are the roles of prostaglandins in the production of gastric secretions?
Prostaglandin E2 stimulates the secretion of both mucus and bicarbonate from cells in the gastric mucosa, both of which are protective against stomach acid. • Why would diphenhydramine, a H1 antihistamine, be useless in the treatment of a peptic ulcer? Diphenhydramine is an antihistamine, which acts on H1 receptors, not H2 receptors that are found in the stomach parietal cells. • Antacids are relatively cheap and have been shown to heal peptic ulcers, but are rarely used as the sole treatment for such ulcers. Why? Antacids neutralise hydrochloric acid and to a certain extent inhibit pepsin activity in the stomach. These actions are related to each other as if the pH of the gastric contents rises above 4, pepsin activity is inhibited. Both pepsin and hydrochloric acid are involved in the aetiology of ulcers. Antacids taken for a long time and in large amounts are effective in allowing an ulcer to heal. The problem here is the large amounts that have to be taken. It has been known for pa
