Modulation of dietary fat-promoted pancreatic carcinogenesis in rats and hamsters by chronic ethanol ingestion

Abstract

The effect of chronic ethanol ingestion on dietary fat-promoted pancreatic carcinogenesis was investigated in rats and hamsters. Rats were given a single i.p. injection of 30 mg azaserine per kg body wt at 19 days of age. Hamsters were injected s.c. with 20 mg N-nitrosobis(2-oxopropyl)amine (BOP) per kg body wt at 6 and 7 weeks of age. The animals were fed a semi-purified diet high in unsaturated fat (25% corn oil) either separately or in combination with ethanol. Ethanol was provided in drinking water at a concentration of 10% (w/v). A separate group maintained on a diet low in unsaturated fat (5% corn oil) was included as extra controls. The rats and hamsters were given their diets and received ethanol via their drinking water after treatment with carcinogen. Terminal autopsy of rats was 15 months after azaserine treatment and of hamsters 12 months after the last injection with BOP. Dietary fat was found to enhance pancreatic carcinogenesis in both rats and hamsters. In rats, ethanol slightly enhanced the multiplicity but not the incidence of malignant tumours, while in hamsters ethanol did not show any modulating effect on dietary fat-promoted carcinogenesis. It was concluded that dietary fat-promoted pancreatic carcinogenesis as observed in the animal models applied is not significantly modulated by chronic ethanol ingestion.