Aspirin-like drugs, ethanol-induced rat gastric injury and mucosal eicosanoid release.

The effect of oral administration of various non-steroidal antiinflammatory drugs on ethanol-induced rat gastric injury and mucosal release of leukotriene C4, 6-keto-prostaglandin F1 alpha and 15-hydroxy-5,8,11,13-eicosatetraenoic acid was investigated. It was found that besides sodium salicylate and high doses of aspirin, other salicylate-type drugs, such as diflunisal, 4-aminosalicylic acid, 2,4-dihydroxybenzoic acid and methyl salicylate, and several non-acidic compounds, such as proquazone, benzydamine and paracetamol, were gastroprotective. All these drugs inhibited ex vivo leukotriene C4 formation by ethanol-stimulated gastric mucosa. However, naproxen, lonazolac, ibuprofen, gentisic acid and 5-aminosalicylic acid also inhibited leukotriene C4 formation, but were not protective. Gastroprotection was independent of 6-keto-prostaglandin F1 alpha formation. Both protective and non-protective drugs inhibited the ethanol-stimulated, but not the basal, release of 15-hydroxy-5,8,11,13-eicosatetraenoic acid. The results indicate that the differential effects of various non-steroidal antiinflammatory drugs on gastroprotection against ethanol are not correlated with specific effects on mucosal cyclooxygenase, 5-lipoxygenase or 15-lipoxygenase activity.