Osteoporosis (OP)

Osteoporosis is a degenerative bone disease that primarily affects post-menopausal women. It is characterized by a decrease in normal bone density due to the loss of calcium and collagen. As a consequence of decreased bone density, bones become brittle resulting in frequent fractures and other serious effects. Bone loss increases after menopause due to lower levels of estrogen. Osteoporosis may also occur due to a number of diseases or treatments including alcoholism, anorexia, hyperthyroidism, surgical removal of the ovaries, and kidney disease. Studies show that osteoporosis model induced by ovariectomy are used to provide a useful model for prevention and therapy of osteoporosis. Retinoic acid ( RA）and hydrocortisone are usually used to induce the model for osteoporosis.