[Effects of the contamination by polychlorobiphenyls (PCBs) on the growth of the Ehrlich tumor in mice (author's transl)].

The effects of a 3-month experimental contamination with a commercial mixture of PCBs, DP5 (corresponding to Aroclor 1254) have been studied on groups of 25 SWISS female mice, at levels of 0, 10, 50 and 250 ppm added at feeding. After subcutaneous injection of 0,2 ml of Ehrlich's tumoral ascites liquid, the evolution of tumors as well as the mortality level, were different in the treated groups as compared to the control group. The percentages of mortality due to tumors were the following: control (0 ppm) = 50% 10 ppm = 5% 50 ppm = 5% 250 ppm = 35% Thus, contamination by PCBs seems to have protected these mice against the Ehrlich tumor. No decrease in body weight was noted neither were differences in size or appearance of the thymus and the spleen in the treated mice; an evident liver hypertrophy was noted in all PCB treated mice.