ABSTRACT
Objective 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.
ABSTRACT
Objective To observe the impact of coal-burning-borne fluorosis on the opening day of vagina,and estrogen cycle and endocrinology of female rat.Methods Ninety weaned two weeks and healthy female SD rats,weighing 60-80 g were selected,and divided into three groups by body weight using random number table:control group,moderate fluoride exposed group,and higher fluoride exposed group,thirty rates in each group.Rats in fluoride exposed groups were fed with baked corn collected from coal-burning-borne fluorosis areas containing different levels of fluorine(fluorine contents were 47.8 and 96.0 mg/kg,respectively) to establish coal-burning-borne fluorosis models.The corn fed to control group rats were collected from non-endemic areas (fluoride content was 5.2 mg/kg).After exposed to fluoride for 60,120 and 180 days,the rats were put to death during estrus in three batches (10 rats in every batche).The situation of female vaginal opening was observed and recorded every morning at 8:00 at the beginning of the experiment.Ten female rats in each group were randomly selected to observe vaginal exfoliated cells for 10 days continuously every morning,and HE staining was selected to discriminate estrogen cycle.Femoral artery blood was collected to observe the impact of estradiol(E2) in estrus.Results The vaginal opening day age of the longer fluoride exposed group [(49.0 ± 4.5)d] was longer than that of the control group[(45.4 ± 2.3)d] and the moderate fluoride exposed group[(46.7 ± 1.9)d,all P ＜ 0.05].Estrogen cycle of the longer fluoride exposed group[(5.8 ± 0.8)d] after fluoride exposure for 120 d was higher than that of the control group [(4.4 + 0.9)d] and the moderate fluoride exposed group [(4.9 ± 0.7)d,all P ＜ 0.05].Estrogen cycle increased with increasing dosage of fluoride after fluoride exposure for 180 d in three groups [control group:(4.3 ± 0.7)d,moderate fluoride exposed group:(5.4 ± 1.1)d,higher fluoride exposed group:(6.7 + 0.9)d,all P ＜ 0.05].Estrogen cycle in higher fluoride exposed group at 180 d[(6.7 ± 0.9)d] was higher than that of 60 d and 120 d[(5.2 ± 1.1),(5.8 ± 0.8)d,all P ＜ 0.05].At 60 d after exposed to fluoride,E2 levels of fluoride exposed groups were increased[control group:(30.125 ± 94.17)ng/L,moderate fluoride exposed group:(438.75 ± 71.80) ng/L],higher fluoride exposed group (456.25 ± 57.80)ng/L with increasing dosage of fluoride (all P ＜ 0.05).E2 level in rats exposed to fluoride for 180 d [(275.00 ± 127.83)ng/L] was lower than that of 60 d and 120 d [(456.25 ± 57.80),(392.50 ± 102.50)ng/L,all P ＜ 0.05] in higher fluoride exposed groups.Conclusions Coal-burning-borne fluorosis has a significant effect on vaginal opening day age,estrogen cycle and endocrinology of female rats.The higher the fluoride dose,and the longer the exposure time,the more severe the impact.
ABSTRACT
<p><b>OBJECTIVE</b>To establish a long-standing cell line of esophageal squamous cell carcinoma (ESCC) in pursuit of a model for in vitro study of carcinogenesis.</p><p><b>METHODS</b>Small tissue blocks taken from resected specimens of esophageal cancer were cultured, and cell line EC9706 was established. The biologic properties of EC9706 were characterized. Comparative genomic hybridization(CGH) was performed on the cell line.</p><p><b>RESULTS</b>The growth curve of EC9706 was detected. The cell generation time was 26 hours. The plate colony forming efficiency is 91.9%, with the capacity of forming clones in soft agar. EC9706 cells show high tumorigenecity as indicated by the rapid regeneration of moderate-poor-differentiated squamous cell carcinomas after injection into nude mice. CGH analysis indicated copy number gains of 1p1, 1q2-4, 2p1, 2q1, 5p, 7p14, 7q21, 11q1, 15q2, 20q and losses of 2p2, 2q2, 3p, 4, 9p, 14, 18, Xq. High-level gain of 5p was observed.</p><p><b>CONCLUSION</b>Established cell line EC9706 can serve as a useful tool for studying the carcinogenesis of ESCC.</p>