Possible role of sulfhydryls in mucosal protection induced by aluminum hydroxide.

The involvement of sulfhydryl-containing compounds was investigated in the cytoprotective effect of certain antacids against ethanol-induced gastric mucosal damage in the rat. Not only the protective effect of a sulfhydryl containing compound, N-acetylcysteine, was abolished after pretreatment with N-ethylmaleimide, but also the adaptive cytoprotection induced by 20% ethanol. Pretreatment of the animals with the cyclooxygenase inhibitor indomethacin or with the thiol reagent N-ethylmaleimide significantly diminished the cytoprotection evoked by aluminum hydroxide. However, the protective effect of aluminium hydroxide could only be totally abolished by pretreatment with the combination of indomethacin and N-ethylmaleimide. The present results suggest the additional role of sulfhydryl-containing compounds localized in the gastric mucosa in the cytoprotection induced by a mild irritant or by aluminium hydroxide and aluminium hydroxide-containing antacids as well.