Polychlorinated biphenyl congener 153-induced ultrastructural alterations in rat hepatocytes: A quantitative study

Alterations occurring in the liver of male and female rats fed PCB congener 153 (2,2$\sp\prime,4,4\sp\prime,5,5\sp\prime$-hexachlorobiphenyl) at concentrations of 0.5, 5, or 50 ppm for 13 weeks were determined morphometrically. A dose-dependent increase of hepatocyte volume was detected in the animals. The cytoplasmic compartment contributed to the increase in cell volume in an overwhelming fashion; nuclear participation in the hypertrophy was slight. A marked increase of smooth endoplasmic reticulum (SER) volume and its surface area in hepatocytes was observed in 5 and 50 ppm groups of both genders; the organelle played the largest part in the increase of cytoplasm volume or hypertrophy of the cells. Rough endoplasmic reticulum (RER) alteration was shown to depend on gender, where its volume per hepatocyte augmented in females of 5 or 50 ppm groups, but decreased values were noted in males at the same dose concentrations. A significant decrease in normal mitochondrial volume at 50 ppm dose was observed. Data revealed a trend toward an increase of abnormal mitochondria volume in the hepatocytes as congener concentration elevated. In addition, an increase in the volume of lysosomal elements per cell was noted in 50 ppm PCB-dosed rats of both genders; an increase in peroxisomal volume per cell of female rats was detected at a lower dose than those in male rats. In conclusion, the present study revealed that subchronic exposure to PCB 153 caused ultrastructural alterations in centrilobular hepatocytes of Sprague-Dawley rats. Cell hypertrophy, SER proliferation, RER volume alterations, mitochondrial abnormalities, and augmentation of peroxisomes and lysosomal elements were the most conspicuous changes. Alterations were dose-dependent and were most severe in 50 ppm groups. (Abstract shortened by UMI.).