燃煤型氟中毒对雌性大鼠卵巢颗粒细胞的影响

Effects of fluorosis caused by coal burning on ovarian granular cells in female rats

目的动态观察燃煤型氟中毒对雌性大鼠卵巢颗粒细胞的影响。方法将清洁级SD雌性大鼠90只随机分为对照组、中氟组、高氟组,每组30只,对照组大鼠食用非病区玉米饲料(含氟量5.2 mg/kg),中氟组和高氟组分别在饲料中添加45%和75%的某病区原煤加拌泥煤烘烤的玉米饲料(含氟量分别为47.8、96.0 mg/kg)。每组分别于60、120、180 d动态观察雌鼠氟斑牙变化情况,测定尿氟、骨氟水平,采用透射电镜观察卵巢颗粒细胞超微结构变化,末端转移酶标记技术(TUNEL法)检测卵巢颗粒细胞凋亡情况。结果成功建立燃煤型氟中毒雌鼠模型。透射电镜下发现,对照组卵巢颗粒细胞形态结构正常;染氟组可见颗粒细胞核膜皱缩,内质网、核糖体逐渐减少,线粒体肿胀,胞浆内出现较多的脂滴,随染氟剂量的增加逐渐出现颗粒细胞凋亡特征。除中氟组染氟60 d时卵巢颗粒细胞凋亡率与对照组差异无统计学意义外(P>0.05),各染氟组雌鼠颗粒细胞凋亡率均高于同期对照组(P<0.05),且随染氟时间的延长和剂量的增加,颗粒细胞凋亡率逐渐增加。结论氟中毒可能通过影响大鼠卵巢颗粒细胞结构,诱导和促进卵巢颗粒细胞凋亡,且颗粒细胞超微结构的损伤程度和凋亡率与染氟时间及剂量有关。

Objective To dynamically observe the effects of fluorosis caused by coal burning on ovarian granular cells in female rats. Methods A total of 90 female mice were randomly devided into three groups, to establish coal fluorosis models in female rats by feeding them with corn powder baked by high fluoride coal （47.8, 96.0 mg/kg）, and to observe dynamically the changes of female rats＇ teeth and uhrastructure of ovarian granular cells by transmission electron microscopy. The fluoride contents of urine and bone were measured, and the level of apoptosis in ovarian granular cells were detected with TUNEL assay. Results The animal model of fluorosis was successfully established. The morphological structure of granular cells was normal all the time in the control group. In the fluorosis group, not only the nucleus distorting , mitochondria swelling and chromatin aggregating at the nuclear membrane were found, but also endoplasmie reticulum and ribosomes gradually reduced with the extension of time. With the increasing of fluoride concentration, granular cells showed apoptotic characters, such as the lacy nuclear membrane shrinking, the nucleolns diminishing or disappearing and the nubbly chromatin aggregating. With TUNEL assay, many apoptotic granular cells that were brown or tawny appeared in the fluorosis group. The apoptosis rate of ovarian granular cell in the fluorosis group was significantly higher than the control group （P〈0.05） except the medium concentration fluoride group and the control group in 60 days exposure, and the apoptosis rate of ovarian granular cell went up gradually with the increasing of fluoride concentration and the exposure of time. Conclusion Fluorosis has adverse effects on structure of granular cells of the rat ovary, and can cause the apoptosis of granular cells,which have correlation with the fluoride concentration and exposure time.