Effects of a polychlorinated biphenyl (PCB) on sleeping times, plasma corticosteroids, and testicular activity of white-footed mice.

Forty adult male white-footed mice (Peromyscus leucopus) were divided into four equal groups and fed diets containing 0, 100, 200 or 400 p.p.m. of a polychlorinated biphenyl (PCB) for 2 weeks. PCB ingestion increased liver weights and reduced pentobarbital-induced sleeping times at all levels tested, indicating increased hepatic microsomal enzyme activity. Plasma corticoid levels, seminal vesicle weights and testicular spermatozoa numbers were reduced at the 400 p.p.m. level.