An ultrastructural-cytochemical study on the proliferation of smooth endoplasmic reticulum induced by chlorobiphenyls (PCB) in the guinea pig liver cells.

The ultrastructural changes in the liver cells of guinea pigs induced by the oral administration of PCB were studied by electron microscopy; also electron-microscopic cytochemistry for glucose-6-phosphatase (G-6-Pase) activity was applied. Proliferation of smooth endoplasmic reticulum (sER) was the most prominent change observed in the liver cells, which remained as long as 90 days after the final administration. G-6-Pase activity was ultracytochemically demonstrated not only in the rough and smooth endoplasmic reticulum and the nuclear envelope in the liver cells of normal controls, but also in the proliferated sER in the liver cells of PCB-treated animals. The present investigation revealed that PCB stored in the animal body induced the proliferation of sER in the liver cells for a long time after the cessation of the treatment, and that sER in the liver cells, normally existing or proliferated, always showed positive activity of G-6-Pase.