Steroid-induced concentric membrane whorls in dog liver.

When daily doses of 10 mg/kg of the androgenic steroids fluoxymesterone, methyltestosterone, testosterone propionate, oxymetholone and mepitiostane were administered to adult male and female beagle dogs for 6 months, concentric membrane whorls were produced in the hepatocytes of all groups. The whorls frequently had a central core mainly composed of lipids or mitochondria and the membranes of the whorls, consisting of paired membranes, continued to the smooth or granular endoplasmic reticulum at the periphery of the structures.