Nitrosamide Formation <italic>In Vivo</italic>: Induction of Lung Adenomas in Swiss Mice by Concurrent Feeding of Nitrite and Methylurea or Ethylurea<xref ref-type="fn" rid="FN2">2</xref>

Abstract

Swiss mice were treated For 6 months with methylurea (5.36 g/kg Food) or ethylurea (6.36 g/kg Food) together with sodium nitrite (1.0 g/Iiter drinking water). In both groups, more than 4 lung adenomas/mouse were induced. The alkyl urea-plus-nitrite groups also had a small increase in malignant lymphomas. Similar treatment with methylurea or ethyl urea alone had no effect. The results indicate that the lung adenomas were induced by methylnitrosourea and ethylnitrosourea, Formed by in vivo nitrosation of the corresponding alkylureas. The possible public health implications of ureide nitrosation in vivo are discussed.