ABSTRACT
Objective To observe the dynamic histological changes of condylar cartilage ,and detect expression of estrogen re‐ceptors and collagen typeⅡin the ovariectomized rat ,exploring the relationship between OA and abnormity of shorting estrogen . Methods Histological changes of condylar cartilage of the ovariectomized rat at different ages were observed by HE staining meth‐od .The expression of estrogen receptors and collagen typeⅡwere determined by immunohistochemical method ,and the average per‐centage of positive staining area was measured by image analyzer .Results The lack of estrogen led to the degeneration of condylar cartilage .The expression of ER and ColⅡ were suppressed at low concentration of estrogen ,and these effects were enhanced when the treating time was prolonged .Conclusion The lack of estrogen might lead to the rat′s condylar cartilage lesion ,and the low con‐centration of estrogen could suppress the expression of ER .These results highlight the results that expression of condylar cartilage collagen is associated with estrogen .