Fluoride and arsenic exposure affects spatial memory and activates the ERK/CREB signaling pathway in offspring rats.

Fluoride and arsenic are inorganic contaminants that occur in the natural environment. Chronic fluoride and/or arsenic exposure can induce developmental neurotoxicity and negatively influence intelligence in children, although the underlying molecular mechanisms are poorly understood. This study explored the effects of fluoride and arsenic exposure in drinking water on spatial learning, memory and key protein expression in the ERK/CREB signaling pathway in hippocampal and cerebral cortex tissue in rat offspring.

[The effect of different concentrations of fluoride on the expression of Smad2/3 in ameloblast of rat incisor].

Purpose: To investigate the effect of different concentrations of fluoride on the expression of Smad2/3 which is a specific intracellular signal transduction molecule of TGF-β, and to explore the mechanism of dental fluorosis in rat.

Methods: Forty Wistar rats were randomly divided into 3 groups.HE and immunohistochemistry were used to detect the changes of the ameloblasts and the expression of Smad2/3 in rat incisors.

[Effect of fluoride on the expression of MMP-20/TIMP-2 in ameloblast of rat incisor and the antagonistic effect of melatonin against fluorosis].

Purpose: To study the effect of concentration of fluoride on the expression of matrix metalloproteinase-20(MMP-20) and tissue inhibitors of metalloproteinase-2 (TIMP-2) in the ameloblast of rat incisor,and explore the formation mechanism of dental fluorosis. By comparing the different expression of MMP-20,TIMP-2 between fluoride group and the melatonin group,to decide whether melatonin has antagonitic effect on dental fluorosis.

Methods: Forty Wistar rats were randomly divided into 6 groups.