[Experience in pair-feeding of rats treated with nitrate or sodium nitrite]. / Expérience en pair-feeding chez des rats traités au nitrate ou au nitrite de sodium.

A nutritional and toxicological study has been made of rats, using the pair-feeding technique. The animals were fed a diet containing 5% of NO-3 ion or 0.5% of NO-2 ion (in the form of sodium salts). Under these conditions, a decrease was noted in the consumption of solid food which caused a net loss of weight. Besides, nitrates notably increase liquid intake and diuresis while nitrites induce a significant decrease in the protein retention coefficient.

[Nutritional and toxicologic impact of nitrates and nitrites administered chronically (6 months) in the rat]. / Impacts nutritionnels et toxicologiques des nitrates et des nitrites administrés chroniquement (6 mois) chez le rat.

It has been made a toxicological, nutritional and histological study of rats fed ad libitum, for six months, with a diet containing respectively (per 100 g of dry food): 0, 0,5 and 5% of NO3- ion and 0, 0,05 and 0,5% of NO2- ion. For each group of treated animals we have paired groups of control animals fed with a diet including the same doses of sodium as NaCl. At the highest dose studied, nitrates and nitrites induce a significative loss of weight during two first months of intoxication, but they do not impair noticeably the classic nutritional parameters of nitrogen metabolism, established at different periods of intoxication (0, 2, 4 and 6 months). Besides, dietary ingestion of relatively important quantities of NO3- and NO2- ions does not induce notable modifications of body composition and blood formula, showing an important adaptation of treated animals. Last, histological observations give evidence to a certain irritation (mucus, oedema) of the anterior section of digestive tract (especially stomach with nitrites), some attacks (essentially with nitrates) of thyroid gland (possible competition with iodine) and kidneys (increased diuresis); but the essential impact, with nitrates and nitrites, is situated at the spleen level, with an important liberation of iron and the trace of haemorrhagic zones, testifying to the chronic struggle of treated animals against methemoglobinemia.

[Transformation of nitrates in the digestive tract of the rat]. / Transformation des nitrates dans le tube digestif, chez le rat

The in vitro transformation of nitrates in nitrites in the various parts of the gastro-intestinal tract has been analysed in the Rat. Results show that nitrites can be found at the different levels of the alimentary tract, especially in the stomach and small intestine. This nitrite production is discussed with regard to the possible formation of nitrosamines in mammals.