摘要目的 观察燃煤污染型氟中毒对雌鼠下丘脑-垂体-卵巢性腺轴系统内分泌的影响,并探索其可能机制.方法 选用60只SD雌鼠,采用随机数字表法,按体质量分为2组:对照组、染氟组,每组30只.对照组食用非病区玉米饲料,染氟组自由食用贵州省织金县燃煤污染型氟中毒病区原煤烘烤的玉米饲料,以复制氟中毒动物模型.观察各组雌鼠染氟期间牙齿变化情况.喂养180 d后,于动情期收集24h尿液,采用氟离子选择电极法测定尿氟含量;动情期处死雌鼠,取右侧长骨采用高温灰化-氟离子选择电极法测定骨氟含量.采用股动脉取血法收集雌鼠血液,分离血清,电化学发光放射免疫法检测血清中卵泡刺激素(FSH)、黄体生成素(LH)、睾酮(T)、雌二醇(E2)、孕酮(P),酶联免疫吸附试验(ELISA)法检测血清中促性腺释放激素(GnRH)、抑制素(INH)含量.分离下丘脑、垂体、卵巢并称重,计算下丘脑、垂体、卵巢的脏器系数;制备组织切片,光镜下观察下丘脑、垂体、卵巢组织形态;电镜观察卵巢组织亚微结构.结果 成功复制实验动物模型.染氟组雌鼠下丘脑、垂体、卵巢脏器系数(0.032±0.004、0.014±0.008、0.037±0.009)与对照组(0.035±0.005、0.012±0.006、0.035±0.004)比较,差异均无统计学意义(t=0.46、0.87、0.64,P均＞0.05).染氟组雌鼠血清GnRH、FSH、LH、T含量[(21.654±4.765)、(29.580±5.221)、(53.988±6.506)、(23.962±2.255)μg/L]均高于对照组[(10.384±2.250)、(19.217±4.743)、(30.314±4.443)、(7.883±1.973) μg/L,t=6.762、4.646、9.503、16.971,P均＜0.05];而P、INH含量[(12.635±3.841)、(18.926±3.465)μg/L]均低于对照组[(21.045±4.768)、(48.076±3.525)μg/L,t=4.344、18.649,P均＜0.05];对照组和染氟组的血清E2含量分别为(35.375±10.662)、(27.500±12.783)μg/L,组间比较差异无统计学意义(t=1.821,P＞ 0.05).2组雌鼠下丘脑、垂体组织光镜、电镜观察结果均无病理改变.光镜下,对照组雌鼠卵巢组织结构形态正常,均可见多个黄体及不同发育阶段的卵泡,颗粒细胞呈单层或多层整齐排列;染氟组雌鼠卵巢间质细胞、颗粒细胞呈高度水肿,卵泡退化增多,成熟卵泡偶见,细胞结构和细胞轮廓变得模糊不清.电镜下,对照组卵巢颗粒细胞超微结构正常,细胞核呈圆形,核内染色质均匀分布,胞质内含有丰富的线粒体及内质网,且形态正常;染氟组卵巢颗粒细胞及间质细胞出现凋亡特征,如核仁消失、线粒体肿胀、染色质在核膜聚集.结论 氟可促使卵巢组织凋亡,破坏微环境,致使卵巢分泌的P、INH减少,下丘脑GnRH和垂体FSH、LH增高,使性腺轴系统分泌异常;氟影响雌鼠性腺轴的部位可能不是下丘脑、垂体,而是卵巢.

abstractsObjective To observe the influence of coal-burning type of fluorosis on hypothalamic-pituitaryovary axis function and to explore possible mechanism in female rats.Methods Sixty SD rats were divided into two groups according to body weight with the method of random number table:control group and fluorosis group,30 rats in each group.Fluorosis group was feed with corn powder baked by high fluorine coal from Zhijin area.Changes of female rats' teeth during fluorine exposure were observed.After feeding for 180 days,24 h urine was collected in estrus and fluorine level was tested using fluoride ion-selective electrode; rats were executed and bone fluorine level was tested with high-temperature ashing-fluorine ion-selective electrode.Femoral artery blood was collected and serum was separated to test the contents of follicle stimulating hormone (FSH),luteinizing hormone (LH),testosterone (T),estradiol (E2) and progesterone (P) with electrochemiluminescence radioimmunoassay and gonadotropin-releasing hormone (GnRH),inhibin (INH) with enzyme-linked immunosorbent assay (ELISA),respectively.Organs,including hypothalamus,pituitary gland and ovary were weighted,and organ coefficients were calculated.Pathological morphology of hypothalamus,pituitary gland and ovary was observed after staining and ultrastructure of ovary was examined by electron microscopy.Results Coal-burning induced fluorine poisoning rat model was established successfully.There were no significant differences statistically in organ coefficients between fluorosis groups (0.032 ± 0.004,0.014 ± 0.008,0.037 ± 0.009) and controls (0.035 ± 0.005,0.012 ± 0.006,0.035 ± 0.004,t =0.46,0.87,0.64,all P ＞ 0.05).Rats serum GnRH,FSH,LH and T levels [(21.654 ± 4.765),(29.580 ± 5.221),(53.988 ± 6.506),(23.962 ± 2.255)μg/L] of fluorosis groups were all higher than those of controls [(10.384 ±2.250),(19.217 ± 4.743),(30.314 ± 4.443),(7.883 ± 1.973)μg/L,t =6.762,4.646,9.503,16.971,all P ＜ 0.05].But the level of P,INH [(12.635 ± 3.841),(18.926 ± 3.465)μg/L] were all lower than those of controls [(21.045 ±4.768),(48.076 ± 3.525)μg/L,t =4.344,18.649,all P ＜ 0.05].Serum E2 levels of control group and fluorosis group were (35.375 ± 10.662) and (27.500 ± 12.783)μg/L,respectively.The difference between groups was not statistically significant (t =1.821,P ＞ 0.05).No pathological changes were observed in the two groups of female hypothalamus,pituitary tissue by light microscopy and electron microscopy.Under light microscope,in the control group of normal ovarian tissue,more corpus luteum and different developmental stages of follicles were seen,granulosa cells were neatly arranged in a monolayer or multilayer.In fluorosis group,severe edema of ovarian interstitial cells and follicle degeneration increased.Cell structure and cell contours were blurred and unclear with occasional mature follicles.Under transmission electron microscope,in control group,normal ovarian granulosa cell ultrastructure was observed,nuclei were round,nuclear chromatin was uniform distributed,cytoplasm was rich in mitochondria and endoplasmic reticulum,and normal morphology.In fluorosis group,granulosa cells and interstitial cells showed apoptotic characters,such as nucleoli disappearing,mitochondrial swelling and chromatin aggregating at the nuclear membrane.Conclusions Fluorosis can induce ovarian tissue apoptosis,severely damage the micro environment.Reduction of P and INH affects ovarian,maturation and ovulation and leads to secretion of GnRH,FSH and LH.Fluorosis caused by coal-burning may induce the injury of ovary and cause abnormal secretion of hypothalamic-pituitary-ovary axis.Fluorosis has affected parts of female axis which may not be in the hypothalamus,pituitary,but causes ovarian tissue damage.