亚慢性砷暴露对大鼠血液和尿液砷含量及运动功能发育的影响

Effects of subchronic arsenic exposure on arsenic content in blood and urine and on motor development of rats

目的研究饮水砷暴露对大鼠运动功能发育的影响及其与大鼠血砷蓄积、尿砷代谢的相关性。方法SPF级初断乳SD大鼠40只,根据预实验LD 50,将大鼠随机分为对照组(0 mg/kg)、低剂量组(1 mg/kg)、中剂量组(2 mg/kg)、高剂量组(10 mg/kg),适应性喂养1周后开始染砷,于染毒的4、8、12周进行大鼠平衡木与悬挂实验。染毒结束进行大鼠趾印实验,采集尿液、血清进行样品砷含量检测。结果中剂量组与高剂量组大鼠的站立时间在任意暴露时间点均少于对照组与低剂量组大鼠(P<0.05);中剂量组与高剂量组大鼠平衡木站立时间均减少(P<0.05);高剂量组大鼠前肢悬挂时间小于对照组与低剂量组大鼠(P<0.05);中剂量组与高剂量组大鼠重复步态次数比对照组与低剂量组大鼠多(P<0.05);中剂量组与高剂量组大鼠大步长度比对照组与低剂量组大鼠少(P<0.05);高剂量组大鼠到达目标物平均时间延长(P<0.05);光镜切片发现染砷组大鼠神经元坏死;大鼠血砷与尿砷呈正相关(P<0.001);大鼠砷代谢与前肢臂力、平衡力、大步长度呈负相关(P<0.001),与大鼠行走重复步态、到达目标物时间呈正相关(P<0.001)。结论提示高砷暴露对大鼠运动功能发育产生负面影响。

Objective To study the effects of arsenic exposure by drinking water on motor function development in rats and the correlation of blood arsenic accumulation and urinary arsenic metabolism in rats.Methods A total of 40 SPF primary weaned SD rats were randomly divided into control group(0 mg/kg),low dose group(1 mg/kg),middle dose group(2 mg/kg),high dose group(10 mg/kg)according to pre-experiment LD 50 Group.Free-feeding water arsenic was started after one week of adaptive feeding,and rat balance beam and suspension experiments were carried out at 4,8,and 12 weeks after exposure.At the end of exposure,toe print test,urine and serum samples were collected to detect arsenic content in rats.Results The standing time of rats in the medium dose group and the high dose group were lower than that in the control group and the low dose group at any exposure time point(P<0.05).The standing time of balance beam of rats in the medium dose group and the high dose group decreased(P<0.05).The forelimb suspension time of rats in the high-dose group was less than that in the control group and the low-dose group(P<0.05).The number of repetitive gait in the middle dose group and the high dose group were higher than that in the control group and the low dose group(P<0.05).The stride length of rats in the medium dose group and the high dose group were less than that in the control group and the low dose group(P<0.05).The average time to reach the target was prolonged in the high-dose group(P<0.05).Neuron necrosis was observed in the rats exposed to arsenic by light microscopy;the blood arsenic was positively correlated with the urinary arsenic in rats(P<0.001);the rat arsenic metabolism was negatively correlated with the forelimb arm strength,balance,and stride length(P<0.001),and was positively correlated with the repeated gait and time of arrival in the rats(P<0.001).Conclusion High arsenic exposure has a negative effect on motor development in rats.