Skin and liver lesions in rats fed a polychlorinated biphenyl mixture
The continuous feeding of the polychlorinated biphenyl mixture Aroclor 1254 to rats produced varying degrees of dermatitis, first on the ears and later on the nose, tail and feet. The lesions were first observed 10 weeks after the rats began eating chow in which the PCB was present. The lesion consisted of alopecia, and the skin was rough, reddened and thickened. Microscopically, there was hyperkeratosis and parakeratosis, and the subcutaneous tissue was edematous, and sometimes infiltrated with inflammatory cells. The lesions were encrusted by desiccated serum which had escaped through small fissures in the epithelium. This lesion was found in 15 of 60 animals fed the PCB at 100 ppm, 4 of 60 at 30 ppm and 1 of 60 at 10 ppm for 10 to 20 weeks. The livers of the PCB-treated rats were enlarged and fluoresced under ultraviolet light. Microscopically, the central lobular hepatocytes were enlarged, there was an accumulation of an iron positive brown pigment in Kupffer cells, and there were central and midzonal foci of necrosis accompanied by inflammation.