[The effects of glucocorticoids on angiogenesis in vitro].

Glucocorticoids administration presumably affects the vascular system and causes avascular necrosis of the femoral head. However, the mechanism by which this occurs is still unknown. In order to clarify the action of glucocorticoids on the vascular system, we investigated the effects of dexamethasone on an angiogenesis model in vitro. The angiogenesis model was obtained by co-culturing vessel fragments and myofibroblastic cells from rat epididymal fat pads. In this model, myofibroblastic cells induce capillary formation by producing an endothelial cell growth factor and collagen. Dexamethasone at physiological doses inhibited significantly capillary growth by suppressing the collagen synthesis by myofibroblastic cells. However, dexamethasone had no effect on endothelial cells. These results indicate that glucocorticoids are related to the pathogenesis of avascular necrosis of the femoral head by inhibiting the repair of the vascular system in vivo.