Carcinogens in rat milk. Transfer of ingested diethylnitrosamine into milk by lactating rats

Mothers of 5-day old rats were given diethylnitrosamine (DEN) (130 mg/kg body weight) by stomach tube. The milk removed from the stomachs of the suckling young contained 5, 16 and 36 parts/10(6) of DEN at 2, 4 and 6 hours respectively after they started suckling the treated mothers. After 49 hours, DEN was no more detectable in the milk.