[Mechanisms of direct gastric mucosal damage by NSAIDs].
Since gastric mucosal membrane, that is the most important part of mucosal barrier, is a lipid-protein layer, ionized and water-soluble NSAIDs are restricted in their transport. In the highly acidic condition of gastric juice, however most of NSAIDs are non-ionized and fat-soluble, dissolve rapidly in lipid-protein layer, and is rapidly absorbed from the acid gastric contents. Within the gastric mucosal cells in neutral condition, NSAIDs are ionized and H+ ions are released. Intracellular NSAIDs cause impairment of gastric mucosal barrier by reduction and alteration of mucous secretion and/or reduction of mucosal ATP. Intracellular H+ ions provoke the mast cells to release histamine which causes mucosal micro-vascular damage. Finally, auto-digestion by gastric juice in this impaired mucosa makes the variegated mucosal lesions.
Kobayashi
Takeaki
T
Department of Internal Medicine, Dokokai Hospital.
Yabana
Tsuyoshi
T
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects* / Q000378:metabolism; D005753:Gastric Mucosa / Q000187:drug effects*; D006801:Humans
D000894:Anti-Inflammatory Agents, Non-Steroidal