The response of LEW and F344 strain rats to the pancreatic
carcinogen azaserine was compared using the size and number of
azaserine-induced acidophilic acinar cell foci and nodules as parameters in a 4-month experiment. A second experiment compared the effect of
corn oil intake by gavage and dietary routes on the growth of
azaserine-induced pancreatic lesions in LEW rats. A third experiment tested the activity of
benzyl acetate in regard to its ability to induce acinar cell foci or to promote the growth of such foci in
azaserine-treated rats. The results showed that equivalent doses of
azaserine induce two to seven times more foci in LEW than in F344 rats, and that LEW rats have a higher incidence of "spontaneous" foci than F344 rats.
Azaserine-treated LEW rats that were given 5 mL
corn oil/kg
body weight 5 days per week by gavage developed more acinar cell foci than rats fed a basal diet (chow). Addition of an equivalent amount of
corn oil to chow had a similar effect of enhancing the development of foci. Rats of neither strain developed acinar cell foci when
benzyl acetate was given by gavage or in the diet nor was there evidence that
benzyl acetate has a significant effect on the development of foci in
azaserine-treated rats. These studies also demonstrate that the
azaserine/rat model of pancreatic
carcinogenesis which was developed in LEW rats can be adapted for use with F344 rats.