How does the H. pylori bacteria cause ulcers?
There are theories as to how this organism causes peptic ulcers. H. pylori produces urease, an enzyme that catalyzes urea to ammonia. The ammonia, which enables the bacteria to survive the acidic environment in the stomach or duodenum, also causes erosions into the mucosal lining and causes epithelial damage. Cytotoxins from the bacteria also damages the epithelium. The organism also produces mucolytic enzymes (protease and lipase) that lead to the degradation of the mucosa, making the epithelium more vulnerable to acid damages. Also, cytokines produced in response to the inflammation may damage the mucosa and lead to ulcer formation. Do aspirin and arthritis medications cause peptic ulcers? Yes, aspirin and NSAIDs (non-steroidal arthritis medications) are known to cause peptic ulcers and severe bleeding. The irritation is both local (on the mucosa of the stomach) and systemic (inhibiting prostaglandin production adversely affecting mucosal defenses, and thinning the blood), leading to
