[Steroid - induced osteoporosis]

Osteoporosis and femoral osteonecrosis are important as main bone lesion caused by the treatment with steroid. Steroid directly inhibits osteoblastgenesis through promotion of apoptosis of osteoblasts and decrease of osteoblast actions. The elucidation at the molecular levels such as decrease of Cbfa1 and TGF-beta type I receptor expression by steroid treatment recently advances. Further, we demonstrated that for the femoral osteonecrosis by steroid, bone marrow tissues concerned also lesions in endothelial cell dysfunctions and in apoptotic cell death. The effects of alendronate on bone quality is noticed recently as a treatments of the steroid-induced osteoporosis.