[Blockade of nitrogen oxide and nitrites by various substances].

The laws by which a number of substances fix nitrogen oxide and sodium nitrite were studied. Nitrogen oxide leads to the formation of compounds of the N O X type, characterised by the following equilibrium constants: 1.93 X 10(-2) for sodium ascorbate, 1.96 X 10(-2) for cysteine, 2.79 X 10(-2) for guanidine, 1.43 X 10(-3) for glutathion, 0.384 for sarcosin, 4.6 X 10(-2) for galacturonic acid, and 1.8 X 10(-3) for neuraminic acid. Mucic, benzoic, lactic and gallic acid do not fix this oxide, nor do glycerol and imidazole. Of all the substances listed above, only ascorbate and cysteine fix nitrite. It was not possible to establish any direct fixing law. This fact, taken with the conditions of the medium, leads to the conclusion that nitrite is fixed only after reduction, in the form of nitrogen oxide NO, according to the laws referred to above.