Morphological changes on nerves and histopathological effects on liver and kidney of rats by pentachlorophenol (PCP).

1. The chronic toxicity of pentachlorophenol (PCP) was studied in rats after 90-120 days of oral administration ad libitum of 0.3-3 mM PCP aqueous solutions. 2. Morphological studies of their sciatic nerves were performed by optical and electron microscopy. 3. They showed degenerative changes in about 10% of the A and B type of nerve fibers. 4. The myelin sheath was discontinued by complete separation in several concentric rings while some other parts of the nerve exhibited a variable loss of neurotubules, neurofilaments and other axoplasmic components. 5. However, the C type of nerve fibers, the blood vessels and the perineurium did not show any morphologic alteration. 6. It was also found that in the liver PCP caused hemodynamic vein changes and injury in the hepatocytes such as cellular swelling and vacuolar degeneration. 7. The damage in the kidney occurred primarily in the glomeruli and secondarily in the proximal tubules causing turbid tumefaction and the formation of casts in the tubular lumen.