甲醛对小鼠认知与运动功能的影响及其机制

目的：研究长时间接触甲醛小鼠认知与运动功能的改变，并初步阐明其作用机制。方法：采用健康昆明种小鼠48只，按照随机分组的原则，将小鼠分为对照组(n=12)和甲醛染毒组(n=36)，染毒组浓度分别是21.0 mg/m³(1/24 LC50)、42.0 mg/m³ (1/12 LC50)和84.0 mg/m³ (1/6 LC50)，每组12只。采用静式吸入染毒，每天2 h，每周 6 d，染毒12周，对照组吸入正常空气。染毒前和染毒第4、8和12周，进行小鼠的认知与运动功能的测试。染毒结束后处死小鼠，检测脑组织琥珀酸脱氢酶(SDH)、Na+-K+ ATPase及Ca2+-Mg2+ATPase活性。结果：在主动逃避实验中，第12周时高剂量组小鼠主动逃避次数低于对照组（P<0.05或P<0.01)。在被动刺激实验中，第12周时中剂量组和高剂量组小鼠被动逃避时间高于对照组（P<0.05或P<0.01)，并且随着染毒时间的推移，小鼠被动逃避时间也发生变化，第12周时高剂量组小鼠所需时间明显长于第4和8周时所需时间（P<0.05)。各染毒组小鼠脑组织SDH含量均下降，高剂量组与对照组比较差异有统计学意义（P<0.05)，各染毒组小鼠脑组织Na+-K+ ATPase和Ca2+-Mg2+ATPase活性均下降，但组间比较差异无统计学意义（P＞0.05)。结论：小鼠长时间接触甲醛可引起认知与运动功能的下降及脑组织细胞代谢水平改变，提示脑组织细胞代谢水平的改变可能是小鼠认知与运动功能下降的原因之一。

Effects of formaldehyde on cognition and moter function in mice and their potential mechanisms

Objective To study the effects of long-term exposure to formaldehyde on cognition and motor function of mice,and explore the potential mechanisms.Methods 48 Kunming mice were randomly divided into 4 groups: negative control and low,middle and high dose formaldehyde groups(21.0,42.0 and 84.0 mg·m-3).The mice were exposed to formaldehyde by inspiration in a static total enclosure chamber for 12 weeks.Before exposed to formaldehyde and at 4th week,8th week and 12th week,cognition and motor function of mice were determined.At 12th week,the mice were killed,the activities of succinate dehydrogenase(SDH),Na+-K+ ATPase and Ca2+-Mg2+ATPase in the brain tissues were detected.Results At the test of initiative escape,the times of initiative escape in high dose group were significantly decreased compared with control group at the 12th week(P<0.05).At the test of passive escape,at the 12th week,the time of passive escape of the mice in middle dose group and high dose group was increased,and there was significant difference compared with control group(P<0.05 or P<0.01).With extending of exposure to formaldehyde,the time of passive escape had changed.At 12th week,the escaping time in high dose group was significantly increased compared with the 4th week and the 8th week(P<0.05).The SDH activities were decreased in formaldehyde groups,and there was significant differences between high dose group and control group(P<0.05);the activities of Na+-K+ ATPase and Ca2+-Mg2+ATPase were decreased in formaldehyde groups,but there were no significant differences compared with control group(P>0.05).Conclusion Long-term exposure to formaldehyde can decrease of cognition and motor function and the change of energy metabolism of brain tissue of mice,indicating that the decrease of energy metabolism may be the potential mechanisms of decrease of cognition and motor function.