噪声对小鼠学习记忆及脑超氧化物歧化酶活力和丙二醛含量的影响

Effect of noise on learning,memory and the activities of SOD and MDA in brain tissue

目的观察噪声对小鼠学习记忆及脑组织超氧化物歧化酶(SOD)、丙二醛(MDA)的影响。方法将144只昆明小鼠,随机分为对照组、80 dB(A)和100 dB(A)噪声组,噪声持续暴露1个月。噪声停止后第1、20、30和40天,分别用Morris水迷宫测试小鼠学习记忆,黄嘌呤氧化酶法测定SOD活力,硫代巴比妥酸比色法测定MDA含量。结果噪声停止时,3组小鼠逃避潜伏分别为(38.35±12.44)、(68.49±17.88)和(89.32±22.62)s,跨台次数分别为(7.25±1.91)、(4.32±1.28)和(3.01±1.01)次,SOD活力分别为(281.53±110.66)、(166.98±61.42)和(104.18±39.12)kU/g,MDA含量分别为(1.23±0.80)、(2.68±1.10)、(4.16±1.32)μmol/g,各指标组间比较差异均有显著性(P<0.05)。噪声停止后第30天,80 dB(A)噪声组小鼠上述指标与对照组比较,差异无显著性(P>0.05);噪声停止后第40天,3个组间的各指标比较,差异均无显著性(P>0.05)。结论噪声能降低小鼠脑组织SOD活力,增加MDA含量,降低小鼠学习记忆。脱离噪声后,小鼠脑组织SOD活力和学习记忆均能恢复,噪声强度越大,恢复需要的时间越长。

Objective To observe the effect of noise exposure on the capability of learning, memory and the acfivivies of superoxidase dismutase （SOD） and malonaldehyde （MDA） in brain tissue of mice. Methods 144 mice were randomly divided into control group ,80 dB（A） noise group and 100 dB（A） noise group. The noise groups were exposed to noise for one month. The capabilities of learning and memory of mice were measured by means of Morris water maze test. The activity of SOD was measured by xanthine oxidase method. The content of MDA was measured by thio-malonylurea colorimetric method. Results Tested just after the noise exposure, among three groups the differences of the average escape incubation period （P 〈 0. 05 ） ,the frequency to bestride platform （ P 〈 0. 05 ）, SOD activities and MDA contents （ P 〈 0. 05 ） were all significant. 30 days after the noise exposure ended, there were no significance difference （P 〉 0. 05 ） between the 80 dB（A） noise group and the control group in the above indexes. Conclusion Noise exposure can reduce the activity of SOD and increase the content of MDA in brain. The abilities of study and memory in mice were also reduced. After the noise exposure ended, the activity of SOD in brain, the learning and memory abilities of mice can be restored. While the louder noise, the longer the time of restoration needed.