Methaemoglobin Formation in Vitro by 6‐Amino Metabolites of DNOC and DNBP

The six compounds DNOC, DNBP, 6‐ANOC, 6‐ANBP, 6‐AcANOC and 6‐AcANBP were investigated for their methaemoglobin‐forming effect on bovine erythrocytes in vitro, and also, for comparative reasons, on erythrocytes from horse, dog, pig and man. Only the amino‐nitrophenols showed any methaemoglobin‐forming effect. The activity was somewhat different for the different species, the haemoglobin in dog erythrocytes in particular being more easily oxidized than the haemoglobin in erythrocytes from the other species. Differences were also recorded between the two amino‐nitrophenols, 6‐ANOC being more active than 6‐ANBP in the bovine erythrocytes, while 6‐ANBP was more active in the pig and horse erythrocytes. In the dog and man there was a little difference between the two substances. The results are discussed in relation to the di‐nitrophenols' comparative toxicology, in particular in relation to the ruminants' special position as regards the metabolism and the toxicity of these substances.