title: Effects of cytotoxic factors of Helicobacter pylori on superoxide generation in situ in the rabbit stomach.
abstract: OBJECTIVE
  To evaluate the effect of certain cytotoxic products of Helicobacter pylori on superoxide generation in situ and on the infiltration by polymorphonuclear cells into the gastric mucosa. The agents studied were ammonia, a culture supernatant of H. pylori, and N-formyl-methionyl-leucyl-phenylalanine (FMLP), a chemotactic factor.
  
  
  METHODS
  One or two of these agents were dripped onto rabbit gastric epithelium. The number of polymorphonuclear cells in gastric mucosa were counted histologically. Superoxide generation was measured by a chemiluminescence method, using a Cypridina luciferin analog, 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one , a chemiluminescence probe that responds to the generation of superoxides and singlet oxygen radicals. Bovine erythrocyte copper zinc superoxide dismutase was dripped to confirm that the increase in photon counts was a direct consequence of the generation of superoxides.
  
  
  RESULTS
  The greatest infiltration of polymorphonuclear cells into the gastric mucosa was observed with the administration of 1 mmol/l FMLP followed by 5.9 mmol/l ammonia, and 10 mmol/l FMLP followed by 59 mmol/l ammonia. There was no increase in the number of polymorphonuclear cells in the other experiments. Increased chemiluminescence was observed in conjunction with the infiltration of polymorphonuclear cells and was inhibited by superoxide dismutase.
  
  
  CONCLUSIONS
  Acute gastritis and superoxide generation in situ were induced by ammonia after pretreatment with FMLP.
authors.affiliation: Department of Internal Medicine 4, Hyogo College of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tamura
authors.forename: M
authors.initials: M
authors.lastname: Yamamura
authors.forename: T
authors.initials: T
authors.lastname: Nishigami
authors.forename: Y
authors.initials: Y
authors.lastname: Tonokatsu
authors.forename: I
authors.initials: I
authors.lastname: Yamamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Fukuda
authors.forename: M
authors.initials: M
authors.lastname: Satomi
authors.forename: T
authors.initials: T
authors.lastname: Shimoyama
mesh_terms: D000641:Ammonia / Q000494:pharmacology; D000818:Animals; D003603:Cytotoxins / Q000633:toxicity*; D005753:Gastric Mucosa / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D016481:Helicobacter Infections / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology*; D016480:Helicobacter pylori / Q000378:metabolism / Q000472:pathogenicity*; D008163:Luminescent Measurements; D008297:Male; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000502:physiology; D011817:Rabbits; D013481:Superoxides / Q000378:metabolism*
chemical_list: D003603:Cytotoxins; D013481:Superoxides; D009240:N-Formylmethionine Leucyl-Phenylalanine; D000641:Ammonia