雌激素改变对大鼠髁突雌激素受体表达及形态的影响

The effect of shifting of estrogen level on the expression of estrogen receptor and morphology of condyle in rat

目的 :探讨雌激素在髁突形态学改变过程中可能的作用及机制。方法 :40只6周龄健康未孕雌性SD大鼠,随机平均分为对照组、避孕药组、避孕药+生理盐水组和避孕药+雌二醇组。实验前和第12周、16周分别检测血清雌二醇浓度,实验结束后处死大鼠,检测髁突软骨ERα和ERβ的表达,观察髁突形态学改变。采用SPSS11.0软件包对数据进行统计学分析。结果:血清雌二醇浓度检测结果显示,第12周时,与对照组相比,各组血清雌激素浓度均显著降低(P<0.05);第16周时,与避孕药+生理盐水组相比,避孕药+雌二醇组血清雌二醇浓度显著上升(P<0.05)。H-E染色及免疫组织化学结果显示,与对照组相比,避孕药组大鼠髁突软骨发生退行性改变,ERα、ERβ表达均显著降低(P<0.05);与避孕药+生理盐水组相比,避孕药+雌二醇组退变的髁突软骨出现修复改变,ERα表达升高(P<0.05),ERβ表达无显著改变(P>0.05)。结论:雌激素浓度降低可出现髁突软骨退行性变,而使用戊酸雌二醇可提高血清雌激素浓度,增加ERα表达,并可能通过ER途径介导完成缓解髁突软骨退行性变的过程。

PURPOSE： To evaluate the possible role and mechanism of estrogen in the morphologic alteration process of mandibular condyle. METHODS： Forty healthy non-pregnant female 6-week-old Sprague-Dawley rats were randomly divided into control group, contraceptive group（intragastric administration with contraceptive）, contraceptive ＋ normal saline（intragastric administration with contraceptive and normal saline） and contraceptive ＋estradiol group（intragastric administration with contraceptive and estradiol） equally. The serum levels of estradiol were detected respectively before the experiment, on the twelfth week and sixteenth week. The rats were sacrificed after the experiment and the expression of ERα, ERβ of condyle was detected and histologic observation of the condyle was performed. SPSS11.0 software package was used for statistical analysis. RESULTS： The serum estradiol concentration of the other 3 groups were significantly lower than control group at 12 week（P〈0.05）; the serum estradiol concentration of contraceptive ＋ estradiol group was significantly higher than contraceptive ＋ normal saline group on sixteenth week（P〈0.05）. H-E and immunohistochemistry showed that compared with control group, not only retrogression occurred in rat condylar cartilage but also the expression of ERα and ERβ of condylar cartilage was decreased（P〈0.05） in contraceptive group; Compared with the contraceptive ＋normal saline group, the retrogression was repaired and ERαexpression was increased（P 〉0.05） while ERβ was not increased（P〈 0.05） in contraceptive ＋ estradiol group. CONCLUSIONS： The lowered serum estrogen would lead to retrogression in condylar cartilage. Estradiol valerate could be used to raise concentration of serum estrogen, increase the expression of ERα and slow down the process of condylar cartilage retrogression through ER pathway.