Steroid-induced accumulation of lipid in the osteocytes of the rabbit femoral head. A histochemical and electron microscopic study.

A high dose of methylprednisolone was administered intramuscularly to rabbits, and we studied the accumulation of lipid in the osteocytes of the femoral head by histochemical methods and electron microscopy. Advanced hyperlipidemia and a fatty liver were observed in four weeks. Electron microscopy was used to define the ultrastructural changes in osteocytes, which showed small lipid droplets that gradually enlarged, finally resulting in the formation of vacuolated vesicles. An increase in the size of the lipid droplets caused them to compress the nucleus to one side of the lacuna, resulting in discontinuities of the cell membrane followed by cell disintegration. These observations demonstrate the effect on osteocytes of a disturbance in lipid metabolism caused by the administration of large doses of steroids.