| Coal-burning endemic fluorosis is a kind of typical local disease. Guizhou Province is a high prevalence area of dental fluorosis from coal-burning. Disequilibrium of calcium homeostasis in dental fluorosis pathogenesis has become a hot research, but the excess fluoride on teeth development in calcium homeostasis specific impact study is less. The team previous research on calcium ion channel related factors including Atp1a1, Atp2b1, Cacna1 and NCX1, but two key factors in our previous studies did not show including NCX3 and NCKX4. This experiment by copying the coal-burning fluorosis animal model of SD rats,and the born of 1, 3, 5, 7, 9 day rats teeth germ tissue will be detected of NCX3 and NCKX4,further exploration of the relationship between the coal-burning fluorosis and calcium homeostasis. On the other hand,ALP is a factor for clinical diagnosis of fluororsis bone tissue,detecting in born of 1, 2, 3 weeks rats serum,observing differentially expression between experimental group and controlled group, to explore the effects of fluorosis on offspring ALP activity, further investigating the coal-burning fluoride effects on offspring. These studies will provide theoretical basis for the prevention and treatment of coal-burning fluorosis.Objective: To investigatethe effect and its mechanism of sodium-calcium exchanger on coal-burning of fluorosis rats teeth germ tissue, the expression of NCX3, NCKX4 and ALP were tested in this study.Methods: 1. Establishment of coal-burning fluorosis animal models: 36 clean level SD rats 3 weeks old, male and female ratio 2:1 were randomly divided into the experimental group and the control group with 18 rats in each group. The experimental group was placed in an indoor environment of simulated coal-burning fluorosis areas, and the feed containing 42.05 mg/kg fluoride. The control group was placed in the normal air environment and fed with normal diet. The rats of two groups drank tap water. 2. The testing contents and methods: the weights of the rats were weighed every week, and incisors of rats were recorded by camera at labial side. The changes of the color of the rat’s incisors were observed. Urine and blood were collected at the same time, and the constraction of fluoride was detected by electrode method. After the animel model was established, the experimental group and the control group of rats respectively according to the proportion of male and female 2:1 cagedin order to litter. To be born 1, 3, 5, 7, 9 days, the rats were executed and under the stereomicroscope separation extraction of teeth germ. The changes of ameloblas were observed by HE staining as well as the histological localization and expression of NCX3 and NCKX4 were tested by immunohistochemical technique and Real-Time PCR. Blood sampling was carried out on 1st, 2ed and 3rd weeks. The serum was isolated and the expression of ALP was detected.Results: 1. Coal-burning fluorosis animal model was successfully established. In the fourth week, there are white spots or patches in the middle part of the teeth. In sixth weeks, the white stripes dense, chalky area more than 75% teeth. In eighth weeks, the whole tooth surface presents chalk white matte enamel. 2. From 1st weeks to 3rd weeks, the ALP levels of fluoride in experimental group increased gradually, while it decreased in the control group. But the ALP level ofthe rats in the experimental group was higher than that of in the control group at the same time(P<0.05).3. In the control group, the enamel cells were closely arranged in the grating, tall columnar the secretory phase, and short columnar in the mature stage. But in the experimental group, the enamel cells were derangemed in disorder, swelling, vacuolar degeneration, and the hemidesmosomes were not closely connected. 4. The calmodulin NCX3, NCKX4 were located in the in the ameloblast. The IOD/AREA expression of NCX3, NCKX4 was inhibited(P< 0.05 or P< 0.01) in 1st, 3rd, 5th, 7th, 9th days.5.Compared with the control group, the m RNA levels of NCX3 and NCKX4 was increased in the 1st day of the experimental group rats(P > 0.05), but was inhibited in 3rd, 5th, 7th, and 9th days(P< 0.05 or P < 0.01).Conclusion: The mechanisms of coal-burning dental fluorosis are related with the expression of NCX3, NCKX4. |
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