[Effect of estrogen-deficiency on expression of osteoprotegerin in alveolar bone: experiment with rats with periodontitis].
OBJECTIVE
To investigate the effects of estrogen-deficiency upon the expression of osteoprotegerin (OPG) in alveolar bone so as to clarify the role of estrogen in alveolar bone metabolism.


METHODS
Fifty-three SD rats were randomly divided into 3 groups: OVX group (n=18) undergoing bilateral ovariectomy, OVX + E2 group (n=18), undergoing bilateral ovariectomy and subcutaneous injection of estradiol once 3 days since day 2 after the operation, and sham operation group (n=17) undergoing sham operation. Four weeks after the operation periodontal ligature was conducted and high-sugar diet was fed to establish periodontitis models. Four weeks later the rats were killed. The morphological changes and expression of OPG in alveolar bone were observed by light microscopy and immunohistochemistry.


RESULTS
All the rats showed sparseness of bone trabeculae in alveolar bone and osteoclasts and lacuna at the surface of alveolar bone, especially the rate of the group OVX. The A values (absorption of the OPG expression) in the alveolar bone of the OVX groups was 27 854 +/- 5246, significantly lower than those of the sham operation group and OVX + E2 group (38 799 +/- 6228 and 37 146 +/- 6394 respectively, both P < 0.05) without significant difference between the sham operation group and OVX + E2 group (P > 0.05).


CONCLUSIONS
Estrogen deficiency decreases the expression of OPG in alveolar bone, and enhances the absorption of alveolar bone.
Wang
Yong-lan
YL
Department of Periodontology, Stomatological Hospital, Tianjin Medical University, Tianjin 300070, China. wangyonglan999@tom.com
Fei
Li-si
LS
Jin
Chen-xin
CX
Liu
Shi-you
SY
D000539:Alveolar Process / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D004967:Estrogens / Q000172:deficiency* / Q000494:pharmacology; D005260:Female; D007150:Immunohistochemistry; D053244:Osteoprotegerin / Q000096:biosynthesis*; D010052:Ovariectomy; D010518:Periodontitis / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D004967:Estrogens; D053244:Osteoprotegerin