Effects of 17β-estradiol on the apoptosis and bone resorption in cultured osteoclasts in vitro

?Objective To study the effect of 17β-estradiol(17βE_2) on the apoptosis of cultured osteoclasts and the relationship with the bone resortption of osteoclasts in vitro. Methods 17βE_2 in different concentration was added to osteoclasts culture medium.The ultrastructural changes of osteoclasts were observed with transmission electron microscopy(TEM).The percentage of apoptic osteoclasts were measured with flow cytometry(FCM) and the area and number of resorption pits with scanning electric microscopy. Results 17βE_2 promoted the apoptosis of osteoclasts in vitro in a dose- and time- dependent manner.The area and number of the resorption pits decreased. Conclusions 17βE_2 can induce apoptosis of osteoclasts in vitro,while inhibit the bone resorption.