Helicobacter pylori decreases gastric mucosal glutathione

Activation of oxidative stress pathways may contribute to gastric epithelia l damage and mutagenesis caused by Helicobacter pylori. We measured the eff ect of H. pylori on the concentrations of reduced glutathione (GSH), an imp ortant endogenous defense against oxidant damage, in gastric epithelial cel ls in vivo and in vitro. GSH concentrations were significantly lower in gas tric biopsies from 19 H. pylori-infected patients than 38 normal controls, and correlated inversely with inflammatory cell numbers. In vitro, H. pylor i initially increased GSH levels in AGS cells, but subsequently depleted in tracellular GSH stores completely after 24 h. No GSH was detected in H. pyl ori. Our data suggest that diminished GSH levels with H. pylori colonizatio n of the gastric mucosa may be due to a direct effect of the bacterium as w ell as through the associated inflammatory response. (C) 2001 Elsevier Scie nce Ireland Ltd. All rights reserved.