次声对大鼠大脑皮层超微结构和单胺氧化酶的影响

Effects of Infrasound on Pallium Ultrastructure and Monoamine Oxidase in Rats

目的观察暴露于8Hz130dB(A)次声不同时间大鼠大脑皮层超微结构和单胺氧化酶(MAO)活力的变化。方法35只雄性SD大鼠随机分为对照组和次声作用1、2、3、4周组。每日暴露2h。取大脑皮层用戊二醛和锇酸固定,透射电镜下观察脑的超微结构的变化和MAO活力改变。结果次声作用后脑损伤以变性改变为主,可见于细胞内外的各种结构。暴露早期随暴露时间延长损伤逐渐加重,暴露后期损伤有一定恢复。MAO活力随暴露时间的延长有增高趋势(29.15±3.53)～(38.50±6.36)IU/gPro,但无统计学意义。结论次声可非特异性地损伤脑的超微结构;在相同的频率和声压级水平下,次声的损伤作用与次声的暴露时间并非呈线性关系。脑组织对次声的损伤有一定的适应性。MAO活力的增高可促进次声对脑组织的损害。

Objective To investigate the changes of pallium ultrastructure and the activity of monoamine oxidase (MAO) in the rats exposed to infrasound with different period. Methods 35 male SD rats were randomly divided into 5 groups. Group 1 served as control group,and other 4 groups were exposed 2 hours per day to 8 Hz 130 dB infrasound for 1,2,3 and 4 weeks respectively. The separated brain was fixed with glutaraldehyde and osmic acid. The changes of the pallium ultrastructure and the activity of MAO were observed under the transmission electron microscope. Results Degeneration was the main change caused by infrasound in brain. It could be observed in all of the intra and extracelluar structure of brain. At the early stage,the damage became more and more serious along with the prolongation of the acting time. At the later stage ,the damage was alleviated to some extent. MAO activities in all the infrasound exposed groups increased ?眼(29.15±3.53)IU/g Pro-(38.50±6.36)IU/g Pro?演 with the prolongation of the acting time,but they showed no significant difference compared with the control group. Conclusion Infrasound could directly damage the pallium ultrastructure nonspecifically. Under the same frequency and same sound pressure level,the infrasound damage on the brain didn't show linear correlation with the acting time of infrasound. The pallium tissues could adapted themselves to infrasound damage. The increasing MAO activities might play an important role in promotion of brain injury.