Gastric ulceration: critical events at the neutrophil--endothelium interface.
Neutrophil adherence to the vascular endothelium and the subsequent release of oxygen-derived free radicals and proteolytic enzymes has been implicated as a critical event in the pathogenesis of various forms of gastrointestinal ulceration. This paper reviews the evidence that events at the neutrophil-endothelium interface are important in the pathogenesis of gastric ulceration induced by nonsteroidal anti-inflammatory drugs (NSAIDs). Endothelial injury occurs within minutes of NSAID administration and appears to be attributable to neutrophil adherence and activation. Neutrophil adherence in response to NSAIDs may occur as a consequence of inhibition of endothelial prostaglandin synthesis, but it appears to involve a lipoxygenase product, such as leukotriene B4. Prevention of neutrophil adherence to the vascular endothelium results in near-complete prevention of experimental NSAID gastropathy. Depletion of circulating neutrophils also results in reduced susceptibility to NSAID-induced mucosal injury. As prostaglandins are potent inhibitors of neutrophil adherence and activation, it is possible that the neutrophil--endothelium interface represents one of the most important targets of action of these compounds in terms of their ability to prevent or reduce the severity of NSAID-induced ulceration.
Gastrointestinal Research Group, Faculty of Medicine, University of Calgary, Alta., Canada.
J L
JL
Wallace
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D004727:Endothelium / Q000502:physiology; D006801:Humans; D009504:Neutrophils / Q000502:physiology*; D013276:Stomach Ulcer / Q000139:chemically induced / Q000503:physiopathology*
D000894:Anti-Inflammatory Agents, Non-Steroidal