2018 Dec 10;220:169-175. doi: 10.1016/j.chemosphere.2018.12.078. [Epub ahead of print]

Effects of drinking water fluorosis on L-type calcium channel of hippocampal neurons in mice.

Yu Q¹, Shao D¹, Zhang R¹, Ouyang W², Zhang Z³.

Author information

1

College of Chemistry and Life Science, Zhejiang Normal University, Jinhua, 321004, PR China.

2

College of Sports and Health Science, Zhejiang Normal University, Jinhua, Zhejiang, 321004, PR China.

3

College of Xing Zhi, Zhejiang Normal University, Jinhua, Zhejiang, 321004, PR China. Electronic address: zzg@zjnu.cn.

Abstract

The study aimed to investigate the effects of drinking water fluorosis on L-type calcium channels (LTCCs) in mouse hippocampal neurons. A total of 60 newly weaned ICR male mice were randomly divided into control, low fluoride and high fluoride groups. After 3 and 6 months of exposure to fluoride, the patch clamp technique was used to detect the peak and relative values (I/Imax), steady-state activation curve ratio (G/Gmax), decay time constant, and tail current time constant of LTCCs currents in hippocampal CA1 region of mouse brain slices. Fluoride greatly reduced the serum and urinary calcium concentrations in mice, and the chronic fluorosis has a greater impact than subchronic fluorosis. The peak value of LTCCs current in pyramidal neurons of hippocampal CA1 area was significant and increased with the prolonged exposure time. The relative values of current and steady-state coefficients were changed greatly. The decay and tail current time increased significantly. High fluorine concentration indicates great peak value and open time of LTCCs opening. LTCCs are sensitive to fluoride exposure. The activation voltage of calcium channels induced by fluoride exposure is decreased, the opening time of calcium channels is prolonged, and the calcium influx per unit time increased, thereby overloading calcium concentration in neurons and this may be an explanation for intracellular calcium overload caused by fluoride. The imbalance of calcium metabolism caused by fluorosis may be a pathogenesis of brain injury induced by fluoride. Furthermore, the risk of brain damage from low-fluorine exposure cannot be ignored.

불소침착증에 의한 칼슘대사의 불균형이 불소로 기인한 뇌손상의 원인이 될 수 있다. 나아가,  저농도 불소노출로 인한 뇌손상 위험도 간과 할 수 없다.

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