Effect of prolonged ingestion of polychlorinated biphenyls on the rat

On a fair consommer a des rats, pendant 2, 4 et 6 mois et a raison de 0,5 et 25 ppm de leur regime alimentaire,de l'Aroclor 1242, melange commercial de biphenyles polychlores. Des augmentations significatives de l'excretion urinaire de coproporphyrine, des lipides hepatiques et de l'activite de l'hydroxylase microsomique hepatique ont ete observees chez les animaux qui avaient consomme 25 ppm pendant 2 mois. L'excretion urinaire de coproporphyrine, le poids du foie, sa teneur en lipides et l'activite de son hydroxylase microsomique etaient plus eleves chez les rats soumis pendant 4 ou 6 mois aux regimes a 5 ou a 25 ppm que chez les animaux temoins. A l'examen histopathologique on a constate une vacuolation des lipides et une proliferation de reticulum endoplasmique dans les hepatocytes des animaux traites. Ces constatations signifient que l'ingestion prolongee de faibles doses d'Aroclor 1242 peut modifier un certain nombre de parametres biologiques.AbstractAroclor 1242, a commercial polychlorinated biphenyl mixture, was fed to rats at dietary levels of 0, 5 and 25 ppm for 2, 4 and 6 months. Significant elevations of urinary coproporphyrin excretion, hepatic lipid and hepatic microsomal-hydroxylase activity were observed in rats ingesting 25 ppm for 2 months. In rats given the 5 or 25 ppm regimens for 4 or 6 months, urinary coproporphyrin excretion and liver weight, lipid content and microsomal-hydroxylase activity were higher than in controls. Histopathological examination revealed lipid vacuolation and proliferation of smooth endoplasmic reticulum in the hepatocytes of treated animals. These findings indicate that long-term, low-level ingestion of Aroclor 1242 may result in changes in a variety of biological parameters.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22345/1/0000791.pd