Carcinogenic response of hamster buccal pouch epithelium to 4 polycyclic aromatic hydrocarbons.

In order to assess the relative carcinogenic potency of polycyclic aromatic hydrocarbons in hamster buccal pouch, groups of male Syrian golden hamsters were treated by painting the buccal pouch surfaces for up to 20 weeks with equimolar concentrations of 7, 12-dimethylbenzanthracene; benzanthracene, 3,4-benzpyrene; or 20-methylcholanthrene dissolved in paraffin oil. Control hamsters were simarily treated with paraffin oil. Whereas 100% of the 7, 12-dimethylbenzanthracene treated hamsters developed buccal pouch carcinomas within the 20-week treatment period, no cancers were observed in the control hamsters or in those treated with the other polycyclic aromatic hydrocarbons. Simarily, of the various treatment groups, only 7,12-dimethylbenzanthracene treated hamsters displayed the efficient induction of foci of intense gamma glutamyltranspeptidase (GGT) histochemical activity within the buccal pouch epithelium. These results support the working hypothesis that induction of GGT foci is an early indicator of developing carcinoma in this experimental model.