Ethinyl oestradiol-induced liver damage in female albino rats

Ethinyl oestradiol (EO) was administered to female albino rats of groups 2, 3 and 4 @ 250, 500 and 750 ¼ g/kg, orally, weekly for 8 weeks, respectively; and the same doses of EO were administered to rats of groups 5, 6 and 7, respectively for 12 weeks. On the 9th week, slight cellular swelling in the liver tissues of group 2 was observed. In group 3, cellular swelling was more marked and the focal areas of hydropic changes were seen. In group 4, the blood vessels including central veins were congested. The hepatocytes revealed nuclear granularity of cytoplasm indicating degenerative changes. On the 12th week, the liver tissues of group 5 showed congestion and perilobular fibrosis. In group 6, severe congestion, focal areas of haemorrhage, and varying degree of degeneration and necrosis were noticed. The central veins were extremely dilated and the fibroblastic proliferation was distinct. In group 7, the histopathological changes were similar to those of group 6; however, the fibroblastic reaction was more intense at the portal triad area and the formation of new bile duct was also evident. The extent and severity of hepatotoxicity were dose and time dependent, indicating that with higher dose and prolonged duration, EO caused severe and extensive damage in the liver tissues. EO at the dose of 500 1/4; g/kg, orally, weekly for 12 weeks is sufficient to cause uniform and optimum liver damage.