The carcinogenic action and metabolism of N-hydroxyurethane in newborn mice.

Abstract

AbstractTen weekly intraperitoneal injections, starting at birth, of N‐hydroxyurethane into C57BL/6 mice, produced thymic lymphosarcomas in 44 per cent and lung adenomas in 78 per cent of survivors. Similar injections of urethane produced lymphosarcomas in 39 per cent and lung adenomas in 75 per cent of survivors.Metabolic studies in newborn C57BL/6 mice, with N‐hydroxyurethane‐14C, demonstrated about 70 per cent conversion into urethane and also the formation of metabolite X (probably a glucuronide). These conversions were similar in extent to those reported for adult mice, but proceeded at slower rates. The reverse conversion of urethane into N‐hydroxyurethane was not detected.These results are consistent with the view that the carcinogenic action of N‐hydroxyurethane proceeds mainly by prior conversion into urethane.