The peritoneal cell carcinogenicity test: Testing of coumarin

Coumarin, a carcinogenic lactone, was tested at single oral doses of 60, 30, and 7.5 mg/kg in Wistar rats using the Peritoneal Cell Test. Two weeks after application, the peritoneal cell were scored on the basis of three for colony growth in soft agar for 7 days. The cultures were scored on the basis of three parameters: colony size, colony frequency, and colony survival until day 7. A fourth parameter, namely the presence of giant colonies of 300 to a few thousand cells, was considered as a further confirmation of the potential carcinogenicity of the agent tested. The results showed positive cultures at all three doses tested, thus confirming the known tumorigenicity of coumarin in rats. Giant colonies were observed in the cultures of rats treated both with coumamrin and dimethylnitrosamine (used as a positive control).