[Formation of nitrosamines in the digestive tract].

Nitrosamines are carcinogenic compounds synthetized from amines and nitrites or nitrates, if nitrates in the reaction medium may be reduced to nitrites. Nitrosation is determined in the digestive tract of several species of laboratory animals. Two physiochemical factors appear to determine in vitro nitrosamine formation: the type of amine and the medium pH. The property of secondary amines to nitrosate is inversely related to amine basicity (checked in vivo), and it increases with the medium acidity. In vitro studies show that different types of bacteria can, even at neutral pH, catalyze nitroamine formation from their precursors. However, the role of digestive tract microbial flora in nitrosamine synthesis in the gut cannot be affirmed due to lack of in vivo studies.