Studies in gastric carcinogenesis. III. The kinetics of nitrosation of gastric-juice components in vitro and their implications for the in vivo formation of N-nitroso compounds in normal and in hypochlorhydric populations

Abstract

Fasting human gastric juice was treated in vitro, at pH 2–7 and 37°C for 2 h, with 5–100 μM sodium nitrite. Under these conditions (which simulated those occurring in vivo in normal or hypochlorhydric individuals), the formation of total N-nitroso compounds had the following characteristics: (i) it increased greatly at pH 5- to 10-fold increase in gastric nitrite concentration relative to that found in the normal population, a condition which is not necessarily fulfilled in all hypochlorhydric individuals or populations. The implications of this conclusion for the assessment of the role on gastric N-nitroso compounds in the etiology of gastric cancer are discussed.