Liver morphology in guinea pigs administered either pyrolysis products of a polychlorinated biphenyl transformer fluid or 2,3,7,8-tetrachlorodibenzo-p-dioxin.

A transformer cooled and insulated with a mixture of 65% Aroclor 1254 and 35% chlorinated benzenes located in the Binghamton State Office Building in Binghamton, New York, was involved in a fire, which produced soot containing polychlorinated biphenyls, biphenylenes, dioxins, and dibenzofurans. A single dose of either soot or 2,3,7,8-tetrachlorodibenzo-p-dioxin in aqueous methyl cellulose was administered by gavage to Hartley guinea pigs of both sexes. The liver tissue was examined 42 days after administration. By light microscopy hypertrophy of hepatocytes, steatosis, focal necrosis, and cytoplasmic hyalin-like bodies were observed as a result of both treatments. Bile duct proliferation (adenofibrosis) was observed only in the guinea pig groups administered soot. These animals also showed proliferation of the smooth endoplasmic reticulum, concentric membrane arrays (CMA), mitochondrial alterations, decreased rough endoplasmic reticulum, and autophagolysosomes by electron microscopy. The CMAs, which corresponded to the hyalin-like bodies, surrounded lipid droplets and cytoplasmic matrix containing mitochondria and degenerating organelles.