Effect of dietary essential fatty acids on pulmonary metastasis of ascites tumor cells in rats.

Abstract

Rats were fed a semi-purified diet supplemented either with a linoleic acid-rich oil (safflower oil) or with an α-linolenic acid-rich oil (perilla oil) from weanling to 7 weeks of age. Rats fed a conventional diet were also used as controls. Ascites tumor cells were injected intravenously into these rats and the numbers of metastatic foci on the pulmonary surface were determined macroscopically. The average number of metastatic foci was significantly less in the rats fed the perilla oil diet than in the rats fed the safflower oil diet or the conventional diet. Combined with previous results on the metastatic potentials of tumor cells modified with different fatty acids, these results indicate that the modification of host animal cells by dietary fatty acids also affects the metastatic potentials of the ascites tumor cells in rats, apparently independently of the tumor cell modifications caused by the supplemented fatty acids.