Lack of dominant lethality in rats treated with polychlorinated biphenyls (Aroclors 1242 and 1254)

Abstract The possible mutagenicity of the polychlorinated biphenyls (PCBs) was investigated using the dominant lethal test. Aroclor 1242 was given to male Osborne-Mendel rats by oral intubation in a single dose of 625, 1250 or 2500 mg/kg, or in five daily doses of 125 or 250 mg/kg. Aroclor 1254 was given by oral intubation in five daily doses of 75, 150 or 300 mg/kg. The rats were then mated with untreated females for the following 10–11 wk. An additional group of male rats given five daily doses of Aroclor 1254 at 150 mg/kg was starved overnight before admittance of females. In a feeding study, males were given Aroclor 1254 at a dietary level of 25 or 100 ppm for 70 days and then were mated with untreated females for 1 wk. Triethylenemelamine (TEM) was used as the positive control compound. Results, except for those obtained with TEM, showed only random, unrepeatable effects that were not related to dose or to the stage of spermatogenesis.