亚磁环境下小鼠生理及运动能力的适应性变化与天人相应理论

目的：探索不同亚磁环境下小鼠生理及运动能力的变化规律，阐释天人相应理论的生物学基础，为未来载人航天生命保障中必须考虑的亚磁效应风险评估提供基础研究依据。方法：8周龄成年雄性C57BL/6小鼠60只，适应性饲养7天后，按照体质量随机分为亥姆霍兹亚磁组、亥姆霍兹对照组、坡莫合金亚磁组、坡莫合金对照组。采用有光照补偿式亥姆霍兹线圈系统(HCS)和无光照屏蔽式坡莫合金亚磁系统（PHS）构建的不同亚磁环境以及相应的地磁场环境进行小鼠长期连续培养，在1个月、3个月、12个月、24个月时，通过热板仪、跑步机、转棒等方法分别检测小鼠热痛觉敏感性，运动能力及身体协调能力的变化。结果：经过3个月亚磁场处理后，坡莫合金亚磁组的热痛觉敏感性明显高于亥姆霍兹对照组、坡莫合金对照组（P<0.01,P<0.05）；亥姆霍兹亚磁组运动能力及身体协调能力明显低于其对照组（P<0.05），且坡莫合金对照组运动能力及身体协调能力明显小于亥姆霍兹对照组（P<0.05,P<0.01）；处理时间12个月时，2种亚磁处理组在热痛觉敏感度上均高于其对照组（P<0.000 1,P<0.01），且坡莫合金对照组小鼠的热痛觉敏感程度要显著高于亥姆霍兹对照组（P<0.05）；2种亚磁处理组运动能力及身体协调能力均明显低于其对照组（P<0.05,P<0.01），坡莫合金亚磁组运动能力及身体协调能力明显低于亥姆霍兹亚磁组（P<0.001,P<0.05），坡莫合金对照组运动能力及身体协调能力明显低于亥姆霍兹对照组（P<0.001,P<0.01）；24个月时，亚磁组小鼠各指标的差异下降，亥姆霍兹亚磁组和坡莫合金亚磁组饮水量明显高于其对照组（P<0.05,P<0.01），饮食量有上升趋势，坡莫合金亚磁组小鼠的空腹血糖水平较其他3组均明显下降（P<0.05,P<0.01,P<0.001）,体质量差异无统计学意义。1个月亚磁处理小鼠各指标暂无差异。结论：长期亚磁场曝露会导致小鼠热痛觉敏感度升高，运动能力及身体协调能力下降，且具有时间累积效应。光照调节可能是挽回亚磁效应的干预途径。

Adaptive Changes of Physiological and Exercise Indexes of Mice in Hypomagnetic Environment and Theory of Correspondence between Nature and Human

To reveal the changes in the physiological indexes and exercise capacity of mice in different hypomagnetic fields,which is necessary for risk assessment and prevention of hypomagnetic effect in the life support system of manned space craft,and elucidate the mechanism underlying the traditional Chinese medicine theory of correspondence between nature and human.Methods:Sixty C57BL/6 mice of 8 weeks old received adaptive feeding for 7 days old and then randomized into Helmholtz hypomagnetic,Helmholtz control,Permalloy hypomagnetic,and Permalloy control groups according to the body weight.The mice were continuously treated in two hypomagnetic environments:the compensative Helmholtz coil system(HCS) with light and the non-light Permalloy-shielded hypomagnetic system(PHS),and in corresponding geomagnetic environments.The changes in the sensitivity to thermal pain,exercise capacity,and motor coordination of the mice were examined by hot plate apparatus,treadmill,and rotarod test,respectively,after 1,3,12,and 24 months.Results:After 3 months of treatment,the Permalloy hypomagnetic group had higher sensitivity to thermal pain than Helmholtz control group and Permalloy control group(P<0.01,P<0.05).The exercise capacity and motor coordination were lower in the Helmholtz hypomagnetic group than in the Helmholtz control group(P<0.05) and lower in the Permalloy control group than in the Helmholtz control group(P<0.05,P<0.01).After 12 months of treatment,the two hypomagnetic treatment groups had higher sensitivity to thermal pain than the control groups(P<0.000 1,P<0.01),and the Permalloy control group had higher sensitivity to thermal pain than the Helmholtz control group(P<0.05).The exercise capacity and motor coordination of the two hypomagnetic groups were lower than those in the control groups(P<0.05,P<0.01).Moreover,the exercise capacity and motor coordination in the Permalloy hypomagnetic group were lower than those in the Helmholtz hypomagnetic group(P<0.001,P<0.05),and they were lower in the Permalloy control group than in the Helmholtz control group(P<0.001,P<0.01).After 24 months of treatment,the differences of the above indexes in the hypomagnetic groups decreased,and the water intake in the Helmholtz and Permalloy hypomagnetic groups was higher than that in the control groups(P<0.05,P<0.01).An upward trend in the diet intake of mice was observed.The fasting blood glucose in the Permalloy hypomagnetic group declined compared with that in the other 3 groups(P<0.05,P<0.01,and P<0.001,respectively).There was no significant difference in the body mass.After one month of treatment,the sensitivity to thermal pain,exercise capacity,and motor coordination showed no significant differences.Conclusion:Long-term exposure to hypomagnetic fields increased the sensitivity to thermal pain and decreased the exercise capacity and motor coordination of mice in a time-dependent manner.The light regulation may be a potential way to antagonize the effects induced by hypomagnetic field exposure.