Pharmaceutics that treat irregularities of the GI system can be divided into three treatment categories:
1. Drugs that decrease gastric acid secretion
2. Drugs that regulate motility
3. Drugs to treat emesis
In this crude drawing from Dr. Scheinman, we see that acid (H+) is secreted by parietal cells lining the intestinal wall. Mucous is secreted by the epithelial cell. Mucous protects the stomach from being eroded be the acidic environment. The first is histamine (HA). HA is released from ECL cells and bind to HA receptors on the parietal cell. The ECL cell releases histamine (HA). Histamine interacts with HA receptors on the parietal cell to increase acid secretion. (+) the activity of the proton pump (H/K ATPase) through signals sent from the histamin receptor to adenylate cyclase to cAMP. Gastrin, an enzyme, also has a favorable effect on the proton pump and will increase acid (H+) secretion when present. Gastrin interacts with the ECL to increase histamine release or can act directly onto the parietal cell.
Prostaglandins (PG) have the opposite effect of HA and gastrin in the . PGs decrease acid secretion. PG receptors are located on epithelial and parietal cells to increasing the secretion of mucous and bicarbonate to neutralize and protect the stomach from being eroded by it's own acid. (NSAIDs decrease the production of PG and therefore can cause
Another player in this drawing is the epithelial cell that
