Gastric cancer in Colombia. IV. Nitrite and other ions in gastric contents of residents from a high-risk region.
Samples of gastric contents from 2 groups of patients from a region of high risk for gastric cancer were analyzed for pH, nitrite, nitrate, thiocyanate, and chloride. In each group, the patients could be divided into 2 subgroups: those with a gastric pH of less than 5 and those with a gastric pH of greater than 5. Above pH 5, nitrite was correlated with nitrate. The pH greater than 5 subgroups had significantly higher (P less than 0.01) nitrite content (20- to 100-fold). Some high- and low-nitrite samples were also analyzed for macro and trace metal ions, but differences were not significant. This is the first report in which patients with diagnosed gastric pathology related to a precancerous state were shown to have high levels of a putative carcinogen precursor. The results were compatible with our original hypothesis of intragastric nitrite formation by bacterial reduction of nitrate and concomitant synthesis of carcinogenic N-nitroso compounds.
D000368:Aged; D002712:Chlorides / Q000032:analysis; D003105:Colombia; D005260:Female; D005750:Gastric Juice / Q000032:analysis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000032:analysis; D009573:Nitrites / Q000032:analysis*; D011230:Precancerous Conditions / Q000032:analysis; D012306:Risk; D013274:Stomach Neoplasms / Q000032:analysis / Q000209:etiology*; D013861:Thiocyanates / Q000032:analysis
D002712:Chlorides; D009566:Nitrates; D009573:Nitrites; D013861:Thiocyanates