Abstract
Cold-restraint stress produced stomach ulceration which was accompanied, by a decreased glandular mucosal mast cell count and blood flow. Pretreatment with FPL55712 a leukotriene antagonist, dosedependently prevented ulcer formation and mast cell depletion; however, it did not affect the reduced mucosal blood flow, nor did it significantly influence acid secretion and pepsin output. The role of the leukotrienes in stress ulceration is discussed in the light of the findings with FPL55712 on gastric glandular mucosal mast cell degranulation.