不同频率次声辐射对小鼠睾丸组织的病理损伤观察

The effects of infrasound on the pathological morphology of mouse testes

目的探讨不同频率次声辐射对小鼠睾丸组织的病理学损伤作用以及连环蛋白（β-catenin）与睾丸损伤间的关系。方法采用随机数字表法将60只成年BALB／C小鼠分为对照组（6只）和次声组（54只），次声组小鼠又根据次声作用频率不同细分为3个亚组，每组18只，分别施以4Hz、8 Hz及20 Hz次声干预（次声声压级均为130dB），持续作用2h；对照组小鼠则于相同时间点置于次声舱内，但期间无次声能量输出。各组分别于次声辐射停止后3h、9h和21h时各取6只小鼠处死（对照组则于上述时间点各取2只处死），提取睾丸组织固定并进行HE染色，观察小鼠睾丸组织病理损伤情况；采用免疫组化技术观察次声作用停止3h后各组小鼠睾丸细胞β—catenin表达情况。结果8Hz-130dB次声辐射对小鼠睾丸的病理损伤作用最显著，可见小鼠精原细胞、精母细胞出现不同程度水肿，细胞结构松散，细胞间连接减少或消失，精子形态受损，并以次声辐射停止3h后病理损伤程度最严重。免疫组化检查结果显示，次声辐射停止3h后，对照组及各次声亚组β—catenin均主要存在于小鼠睾丸间质细胞中，如支持细胞和肌上皮细胞胞膜中均可见强阳性表达，其表达水平与生精细胞周期无关，且不同频率次声亚组β—catenin表达强度无明显差异。结论4Hz-130dB和8Hz-130dB次声辐射均可引起小鼠睾丸细胞形态受损，20Hz-130dB次声辐射则对小鼠睾丸组织无明显损伤作用；次声辐射对小鼠睾丸组织β-catenin表达无明显影响，其损伤效应可能是由次声产生的机械力所致。

Objective To investigate the effects of infrasound at different frequencies on the pathological morphology of mouse testes and to explore the possible involvement of β-cateinin in the mechanism of injury. Methods Sixty adult BALB/C mice were randomly divided into 2 groups. One group of 6 mice were the controls without infrasound exposure. The other group with 54 mice was evenly divided into 3 subgroups of 18 exposed to 130 dB infrasound at 4 Hz, 8 Hz or 20 Hz for 2 hours daily. The pathological morphology of the mice＇s testes was observed 3, 9 and 21 h after exposure. Immunohistochemical staining was used to examine β-catenin expression 3 h after exposure. Results Marked damage was observed in the morphology of the testicular ceils of rats in the 8 Hz group. Cell denaturation was found in germinal cells. The cell structure was loosened and the cell junctions had decreased or disappeared. The damage was most serious at 3 h after exposure. But at the same time point, pathological damage of tes- ticular cells was not obvious in the 4 Hz group, with only a few testes cells swollen. The morphology of testicular tissue of mice in the 20 Hz subgroup exhibited no significant difference from the control group. β-catenin was mainly found in the membranes of Leydig cells, Sertoli cells and myoepithelial ceils in all of the mice, and there was no significant change in the expression level or distribution pattern between the exposed mice and the controls. No expression of β-catenin was found in spermatogenic ceils. Conclusion Infrasound at 4 Hz or 8 Hz can damage testicular tissue, at least in mice. At 20 Hz there is no significant effect on the testes. The loosened cell structure might have been caused by the mechanical force produced by the infrasound and not by any decrease of β-catenin.