Effect of amino acids imbalance and ascorbic acid deficiency on carcinogenic action of N-nitrosopiperidine in guinea pigs.

The long-term maintenances of guinea pigs on diets with (a) lack of vitamin C, (b) lack of lysine, methionine and threonine or (c) with a deficiency of all the above nutrients led to the development of oesophageal hyperplasia and atrophic gastritis. These dietary insufficiences were found to favour oesophageal and gastric cancer production by NPIP with a greatly shortened tumour induction time. It seems likely that the observed features of NPIP carcinogenesis depend on the alteration of the chemistry and biochemistry of these organs provoked by the low intake of the above-mentioned nutrients.