Effects of chronic fluorosis on neurobehavioral development in offspring of rats and antagonistic effect of Vitamin E / 中华地方病学杂志

ABSTRACT

Objective To study the effect of chronic fluorosis on neurobehavioral development,the ability of learning and memory in offspring of rats,and the antagonistic effect of antioxidant Vitamin E (Vit E).Methods According to body weight,forty-five 1-month-old Sprague-Dawley(SD) rats of 30 females and 15 males were divided into three groups by random number table,including control group,fluorosis and Vit E antagonistic groups (15 rats with 10 females and 5 males in every group).Five months after establishing the animal model with chronic fluorosis and Vit E gavage treatments (fluoride ＜ 1,50,50 mg/L,respectively; Vit E 0,0,50 mg/kg,respectively),the rats were mated in 21 proportion of femalemale in different groups,respectively.The fertility index of female and neurobehavioral development indicators in offspring were observed.Spatial learning and memory of offspring after birth for 30 d were evaluated by using Morris Water Maze test.Results The female fertility index exposed to fluorosis and Vit E were not significantly different as compared to those of control group(all P ＞ 0.05) ; in contrast to control groups[(6.4 + 1.8),(15.1 + 1.7)d],the time that completed the surface righting reflex [(8.1 + 1.4),(7.9 + 1.5)d] and the air righting reflex [(17.7 + 2.3),(17.2 + 1.8)d] were delayed in the offspring in fluorosis and Vit E antagonistic groups(all P ＜ 0.05) ; the completed avoidance precipice reflex and the auditory consternation did not changed significantly(all P ＞ 0.05); In addition,compared with control and Vit E antagonistic groups [(31.74 + 17.78),(34.97 ± 15.44)s,(4.50 ± 2.51),(3.80 ± 1.87)time],the average escape latency and exploration platform at five days were decreased in 30 d offspring of fluorosis group[(42.03 + 16.45)s,(2.20 + 1.62)time].Conclusion Neurobehavioral development as well as learning and memory ability in rat offspring are impaired by long-term exposure to fluoride and Vit E has exhibited an antagonistic effect to the toxicities of fluoride.