Physiologic and pathologic roles of prostaglandins and other eicosanoids in bone metabolism.

Prostaglandins are potent regulators of bone formation and bone resorption that can have both stimulatory and inhibitory effects. They are likely to play a central role in the ability of the skeleton to respond to mechanical forces as well as to humoral mediators. The stimulatory and inhibitory responses appear to have different structure-activity relations and signal transduction pathways. Prostaglandin production by both bone and adjacent marrow cells is highly regulated by hormones, cytokines and growth factors, largely through changes in the inducible prostaglandin G/H synthase. Further studies of the role of prostaglandins in bone metabolism may lead to a better understanding of the physiologic and pathologic responses of the skeleton and to new approaches to metabolic bone diseases such as osteoporosis.