title: Cellular mucosal defense is attenuated with chronicity of Helicobacter pylori infection.
abstract: This study assessed the mucosal antioxidant response during acute (mouse) and chronic (adult human) H. pylori infection and following N-acetylcysteine administration. Antral biopsies were obtained from 44 patients (16 infected, 28 noninfected). Sixty-nine mice were sacrificed after 1 (n = 25), 4 (n = 28), or 6 (n = 16) months of infection. A further 29 mice received N-acetylcysteine or water (n = 21) for 14 days following 2.5 weeks of infection. Infected patients showed similar glutathione levels and G6PDH activity to noninfected subjects (P > 0.05). Myeloperoxidase activity was higher in infected patients (P < 0.05). In infected mice, glutathione levels and G6PDH activity were elevated at all time points up 6 months of infection (P < 0.05). Myeloperoxidase activity was increased in infected mice after 1 and 4 months (P < 0.05) but not at 6 months of infection (P > 0.05). N-Acetylcysteine reduced all three parameters in H. pylori-infected mice (P < 0.05). These results suggest an up-regulation of the antioxidant defense system during H. pylori infection in the mouse but not in humans. N-Acetylcysteine reduces the response during infection possibly by lowering the oxidant load.
authors.affiliation: Gastroenterology Department, Women's and Children's Hospital, North Adelaide, South Australia. matthewsg@mail.wch.sa.gov.au
authors.forename: Geoffrey M
authors.initials: GM
authors.lastname: Matthews
authors.forename: David
authors.initials: D
authors.lastname: Tivey
authors.forename: Adrian G
authors.initials: AG
authors.lastname: Cummins
authors.forename: Ross N
authors.initials: RN
authors.lastname: Butler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D005260:Female; D005753:Gastric Mucosa / Q000276:immunology*; D005978:Glutathione / Q000032:analysis; D016481:Helicobacter Infections / Q000276:immunology*; D016480:Helicobacter pylori; D006801:Humans; D007111:Immunity, Cellular; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008875:Middle Aged; D009195:Peroxidase / Q000032:analysis; D013997:Time Factors; D015854:Up-Regulation / Q000502:physiology
chemical_list: D009195:Peroxidase; D005978:Glutathione