Metabolic Fate of the Precursors of N-Nitroso Compounds (I)

The gastro-intestinal absorption of N-nitrosodimethylamine (NDM) and its precursors in guinea-pigs were studied. NDM, dimethylamine (DMA) and nitrate were quite stable in the contents of stomach and small intestine when they were incubated in vitro at 37°C for 60min. Nitrite was stable in the contents of small intestine, but not in those of stomach. DMA and nitrate disappeared from the ligated small intestine, but not from the ligated stomach. Nitrite rapidly disappeared from the ligated stomach, and the rate of disappearance was more rapid than that of decomposition. The disappearance curves of NDM from the ligated stomach and small intestine were monoexponential. NDM rapidly disappeared from the small intestine, and slowly from the stomach.