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 explore the correlation between myeloperoxidase (MPO) genetic variation and coal-burning endemic fluorosis, and to understand the influence of integrated intervention including stove changes and health education on people’s health in the area. Methods In 2007, coal-burning endemic fluorosis disease areas were selected in Bijie City, Guizhou Province. No stove changes in Yachi Town, 150 patients with dental fluorosis were selected as fluorosis non-intervention group, and the intervention group was 150 patients in Changchun Town where the stoves were changed 2 years ago. The population in control group was selected in an area with non-endemic fluorosis in Changshun County. The mRNA expressions of MPO in leukoxytes were detected by real-time PCR. HepG2 cells were cultured in vitro and divided into four groups: pGL3-A group, pGL3-G group, pGL3-Control group and pGL3-Basic group. pGL3-A and pGL3-G were recombinant plasmid, while pGL3-Basic as a blank control and pGL3-Control as a positive one. The internal reference plasmid pRL-TK co-transfected the HepG2 cells with pGL3-G, pGL3-A, pGL3-Basic and pGL3-Control, respectively. The influence of sudden change of MPO gene promoter on the gene transfection activity was evaluated by a dual luciferasereporter gene system. Results The expression level of MPO mRNA in peripheral blood leukocytes in non-intervention group(0.054 ± 0 . 003 ) were higher than control and intervention groups (0.019 ± 0.004,0.019 ± 0.003, all P0.05). After the MPO-463G/A locus genetic variation occured, the luciferase reporter gene expression level of the recombinant plasmid pGL3-G(0.753 4 ± 0.086 6) was higher than that of the pGL3-A(0.490 0 ± 0.022 3, P < 0.05). Conclusions The study on MPO gene promoter-463G/A locus has prompted that MPO gene allele may be a protective factor to coal-burning fluorosis. The integrated interventions have a role in the prevention and treatment of endemic fluorosis.
ABSTRACT
Objective To study the change of bone ?-carboxyglutamic acid containing protein(BGP) in serum of rats at the initial stage of skeletal fluorosis caused by fluoride in coal.Methods SD rats were randomly divided into 6 groups (the number of female and male in each group was the same respectively):the control group,the low-dose fluoride group,the middle-dose fluoride added nutrition group,the middle-dose fluoride group,the high-dose fluoride added nutrition group,the high-dose fluoride group.All rats in the experimental groups were fed on the corn collected from the prevalent areas and contained different contents of fluoride respectively for 90-100 days.Content of fluoride in the urine,bone,kidney,BGP in serum,bone mineral density (BMD)and calcium in the bone and urine were determined.Results The fluorosis of the rats became more serious as fluoride intake increased.On the condition of same fluoride intake,the fluorosis could be relieved if nutrients added.BGP in serum of rats in each experimental groups had a increase trend,at the earlier stage,BGP of the high-dose group was higher than that of the control group (P