Figure 1.

Photomicrographs of new vessel formation (angiogenesis) in the bone marrow of the right femur in the rat model of glucocorticoid-induced osteoporosis (GIOP) treated with dexamethasone or the phosphodiesterase-5 (PDE-5) inhibitors, avanafil and zaprinast. (A) The control (untreated) group. (B) The dexamethasone-treated group. (C) The dexamethasone + zaprinast-treated group. (D) The dexamethasone + avanafil-treated group. The histological tissue sections viewed by light show new vessel formation. Scale bar: 20 μm. Hematoxylin and eosin (H&E).