噪声对豚鼠脑组织抗氧化能力的影响

Effect of noise on antioxidant capacity of brain tissue in guinea pigs

目的 了解噪声对豚鼠脑组织中不同区域抗氧化能力的影响.方法 雄性白色红目豚鼠30只,随机分为5组,噪声暴露后1、3、7、14d组和对照组,每组6只,实验组豚鼠暴露于100 dB声压级（SPL）的稳态白噪声,每天8h,连续2d.检测噪声暴露前和暴露后1、3、7、14 d豚鼠的听性脑干反应（ABR）,并对大脑、小脑、海马中的谷胱甘肽（GSH）、丙二醛（MDA）水平及超氧化物歧化酶（SOD）活力进行测定.结果 噪声暴露后,实验组的ABR阈移均高于对照组,差异有统计学意义（P＜0.05）;噪声暴露后各组大脑组织中的SOD活力和GSH含量均显著低于对照组（P＜0.05）,MDA含量在1d组显著上升（P＜0.05）;7 d组小脑中的SOD活力和GSH含量显著低于对照组（P＜0.05）,各组MDA含量与对照组的差异无统计学意义（P＞0.05）;噪声暴露后1d组中GSH、MDA含量高于对照组,噪声暴露后3d组GSH、MDA含量以及7d组MDA含量低于对照组,差异均有统计学意义（P＜0.05）.结论 噪声暴露导致听力损失的发生,对脑组织的抗氧化能力产生影响,提示通过提高体内抗氧化物质水平可降低噪声对机体的健康损害.

Objective To investigate the effect of noise on the antioxidant capacity in different regions of brain tissue in guinea pigs.Methods Thirty male white red-eye guinea pigs were equally and randomly divided into five groups：1-,3-,7-,and 14-day groups after noise exposure and control group.The guinea pigs of the experimental groups were exposed to steady white noise with a sound pressure level at 100 dB for 8 h per day and for 2 consecutive days.The auditory brainstem response （ABR） of guinea pigs,as well as the glutathione （GSH） level,methane dicarboxylic aldehyde （MDA） level,and superoxide dismutase （SOD） activity in the cerebrum,cerebellum,and hippocampus,was determined prior to and 1,3,7,and 14 days after noise exposure.Results After noise exposure,the shifts in ABR threshold of the experimental groups were significantly higher than that of the control group （P〈0.05）.Compared with those in the control group,the SOD activity and GSH level both significantly decreased in the cerebrum tissue of each experimental group after noise exposure （P〈0.05） and M DA content significantly increased in the 1-day group （P〈0.05）.As for cerebellum tissue,the SOD activity and GSH level in the 7-day group were significantly lower than those in the control group （P〈0.05）,but there was no difference in MDA level between each experimental group and the control group （P〉0.05）.In comparison with those in the control group,the GSH and MDA levels in the 1-day group after noise exposure were significantly higher,and the GSH and MDA levels in the 3-day group and the MDA level in the 7-day group after noise exposure were significantly lower （all P〈0.05）.Conclusion Noise exposure can lead to hearing loss and affect the antioxidant capacity of brain tissue,which indicates that the improvement in antioxidant levels may alleviate noise-induced damage.