What are the cause of stomach ulcers?

Answer 1

Stomach ulcers may be caused by either hyper-secretion of HCl from parietal cells, hypo-secretion of mucus and/or bicarbonate, or by Helicobacter pylori. Hyper-secretion of HCl and hypo-secretion of mucus and/or bicarbonate result in the same problem, it causes damage to the cells lining the inside of the stomach. The mucus and bicarbonate (gastric mucosal barrier) exists to protect the cells of the stomach from mainly HCl. Normally mucus and bicarbonate are secreted at a higher rate than HCl, which allow for protection by slowing its diffusion toward lining and neutralizing the acid before it reach the stomach lining. So if either HCL is increased or mucus and/or bicarbonate decreases acid is able to damage the cells of the stomach. Zollinger-Ellison syndrome, for example, is caused by a tumor that hyper-secretes gastrin, which over stimulates the release of HCl. On the mucus and bicarbonate side, chronic Asprin or other non-steroidal antiinflammatory drug use would be an example. Asprin causes a decrease in mucus and bicarbonate secretion of gastric mucous cells. This may result in either gastritis or gastric ulcers. Also stress can cause ulcers due to the high levels of circulating epinephrine (a stress hormone), which inhibits the secretion of bicarbonate. H. pylori damages the cells of the stomach by illiciting an immune response or by releasing toxic enzymes. Damage to the cells of the stomach results in ulcerations. These bacteria are able to survive in this acidic environment because they produce an enzyme called urease that neutralizes the acid via ammonium (base) production. Since the environment is now less acidic it can bind to cells and gain nutrients from them. At this point it may reproduce causing further damage as the population grows drazx is the original author of this answer.