NEUTROPHIL INFILTRATION DOES NOT CONTRIBUTE TO THE ULCEROGENIC EFFECTS OF INDOMETHACIN IN THE RAT GASTRIC ANTRUM

We have previously suggested (Trevethick et al., Gut 34, 156-160) that indomethacin-induced ulceration of the rat gastric antrum may be a ne utrophil-dependent process. Accordingly, in this study we have used an antineutrophil serum (ANS) to investigate the effects of neutrophil d epletion on this pathology. In animals pretreated with the ANS to indu ce a nearly total neutropaenia, indomethacin-induced increases in bloo d neutrophilia and cell infiltration into the gastric antrum (assessed as LTB(4) release ex vivo) were eliminated. In marked contrast, howev er, ANS pretreatment affected neither the area of mucosa damaged nor t he microscopic characteristics or distribution of the lesions. These r esults suggest that, in contrast to the published reports examining in domethacin-induced ulceration of the gastric fundus, neutrophil infilt ration is not involved in the pathogenesis of indomethacin-induced ulc eration of the rat gastric antrum.