Effects of fluorine exposure on calcium ion metabolism and the expression of related calcium-regulating proteins in the kidneys of rats
10.3760/cma.j.cn231583-20250120-00045
- VernacularTitle:氟暴露对大鼠钙离子代谢及肾脏相关钙调节蛋白表达的影响
- Author:
Yuchen ZHANG
1
;
Yanan LIU
;
Yuting CHEN
;
Yuxi WANG
;
Meichen ZHANG
;
Yanmei YANG
;
Yanhui GAO
;
Xiaona LIU
;
Yang LIU
Author Information
1. 哈尔滨医科大学中国疾病预防控制中心地方病控制中心地氟病防治研究所，哈尔滨 150081
- Publication Type:Journal Article
- Keywords:
Fluorine;
Kidney;
Calcium ion metabolism;
Calcium homeostasis
- From:
Chinese Journal of Endemiology
2025;44(4):279-285
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the effects of fluorine exposure on calcium ion metabolism and the expression of related calcium-regulating proteins in the kidneys of rats.Methods:Forty-five 5-week-old specific pathogen-free male Wistar rats (weighed 90 - 120 g) were selected and divided into three groups according to the randomized numeric table: 0 (control), 50, and 100 mg/L fluorine exposure groups, with 15 rats in each group. The control group was given deionized water, while the 50 and 100 mg/L fluorine exposure groups were given sodium fluoride solutions containing 50 and 100 mg/L fluorine ions, respectively. After 12 weeks, urine samples were collected, and kidneys and blood were harvested. Urinary fluorine levels were measured using a fluoride ion-selective electrode method. Calcium ion levels in the urine, kidneys, and serum were determinated using the methylthymol blue microplate method. The protein expression levels of transient receptor potential vanilloid receptor 5 (TRPV5), calbindin-D28K (CB-D28K), sodium-calcium exchanger-1 (NCX1), Klotho and plasma membrane calcium ATPase 1b (PMCA1b) in the kidneys were detected by Western blotting and immunohistochemistry.Results:The urinary fluorine levels in the control group and the 50 and 100 mg/L fluorine exposure groups were (0.48 ± 0.09), (20.01 ± 1.68), (37.45 ± 2.45) mg/L, respectively, with statistically significant differences between the groups ( F = 929.58, P < 0.001). Significant differences in calcium ion levels in urine, kidneys, and serum were observed among the three groups ( F = 14.66, 11.09, 10.31, P < 0.05). Compared with the control group, the 100 mg/L fluorine exposure group exhibited higher levels of calcium ion in the urine and kidneys, and lower serum calcium ion levels ( P < 0.05). The results of Western blotting analysis revealed that the protein expression levels of TRPV5 and CB-D28K in the kidneys increased with the increase of fluorine exposure level ( Z = 2.11, 2.11, P = 0.035). The protein expression level of NCX1 in the kidneys showed a decreasing trend with increasing fluorine exposure level ( Z = - 2.11, P = 0.035). Significant differences were also observed in the protein expression levels of Klotho and PMCA1b among the three groups ( F = 8.93, 7.08, P < 0.05). Compared with the control group, the 100 mg/L fluorine exposure group showed higher level of Klotho protein expression and lower level of PMCA1b protein expression in the kidneys ( P < 0.05). Immunohistochemical results indicated significant differences in the protein expression levels of TRPV5, CB-D28K, NCX1, and Klotho in the kidneys of the three groups ( F = 27.56, 24.94, 16.05, 32.72, P < 0.05). Compared with the control group, the protein expression levels of TRPV5, CB-D28K, and Klotho in kidneys of 50 and 100 mg/L fluorine exposure groups were higher, while the protein expression levels of NCX1 were lower ( P < 0.05). Conclusion:Fluorine exposure may cause calcium ion metabolism disorders by regulating the expression levels of Klotho and other calcium-regulating proteins in the kidneys.
