Effects of polychlorinated biphenyls (PCB) on fetuses and offsprings were studied in Wistar-SLC pregnant rats fed with the diets containing 0 (control), 10, 50 and 250ppm of PCB (Kanechlor 400). The growth rates of the pregnant rats, the mean numbers of the implants, the rates of the live fetuses and the delivery rates showed no differences between the control and the treated groups. But the body weights of the live fetuses and the 28-day-old offsprings, and the weaning rates decreased significantly in the treated groups. PCB had no teratogenic effects on rats in the doses tested. In serum biochemical tests of 28-day-old offsprings no abnormal findings were found but the decrease of triglyceride. Liver weights of the 28-day-old offsprings increased in the treated groups.
PCB contents of the pregnant rats, their fetuses and offsprings were determined. There was a certain correlation between the contents in the tissues and the doses of PCB. In the pregnant rats, PCB contents were highest in the adipose tissues, and then in the order of livers, kidneys and lungs. PCB concentrations in the fetuses were found lower than in the blood of the pregnant rats but increased markedly in the 14-day-old offsprings, and PCB contents in the tissues of the 28-day-old offsprings were higher than in those of the pregnant rats. Composition of PCB in the rat tissues was different from that of Kanechlor 400 given.