TOXICITY OF PCB-156 IN THE RAT-LIVER - AN ULTRASTRUCTURAL AND BIOCHEMICAL-STUDY

PCB 156 (2,3,3',4,4',5-hexacklorobiphenyl) congener was given to weanl ing Sprague-Dawley rats in diets prepared by mixing it in 4% corn oil. The animals were placed in eight groups, each comprising 10 males or females and received diets that contained 0.01, 0.1, 1, 10 ppm PCB; in addition, two control groups of rats of each gender were given diets mixed with corn oil. Thirteen weeks after commencement of dosing, anim als were euthanized and liver specimens were harvested and prepared fo r transmission electron microscopy. Hepatocyte architectural alteratio ns comprised augmentation of smooth reticulum profiles and mitochondri a with unorthodox cristae in animals regardless of gender from 1 and 1 0 ppm groups. Hepatic microsomal aminopyrine-N-demethylase was elevate d significantly in both genders at highest (10 ppm) congener concentra tion. Based on our previous work, PCB 156 is estimated to be more toxi c than PCB 153 or 28 in terms of liver morphologic expressions.