The development of hepatocellular tumours following aflatoxin B1 exposure of the partially hepatectomised mouse.

The effects of a single i.p. injection of 6 micrograms aflatoxin B1 (AFB1)/g bodyweight, administered 46 h after partial hepatectomy (PH) on the liver of STCF1 mice, were investigated. The study was terminated after 104 weeks. High incidences of hepatocellular carcinomata and adenomata developed in PH mice exposed to AFB1 whereas only background incidences of hepatocellular tumours were observed in non-PH AFB1-exposed mice and in PH or non-PH controls. The regenerative hyperplasia that follows PH appears to promote the carcinogenic effects of AFB1 but does not promote any oncogenic susceptibility present in the control mice. The incidences of lung adenomata and adenocarcinomata were not significantly altered by the single exposure of AFB1.