大鼠肾脏经90 dB或130 dB次声作用后其超微结构的改变

目的探讨大鼠肾脏组织经相同频率(8Hz)，不同声压级水平(90dB及130dB)的次声作用后，其细胞超微结构损伤的特点及意义。方法将雄性SD大鼠78只，随机分为对照组(6只)、实验A组(次声声压级为90dB)及实验B组(次声声压级为130dB)，实验A、B组又根据次声作用时间(1，7，14，21，28和35d)各分为6个亚组，每个亚组有6只大鼠。各组大鼠每天分别在相应声压级水平的8Hz次声环境中暴露1次，每次2h。各组动物待实验结束后处死，取其左、右侧肾组织用戊二醛及锇酸固定，置于透射电镜下观察其超微结构的变化。结果经130dB次声作用1d后，大鼠肾小管上皮细胞间隙略增宽，有轻度线粒体肿胀，而90dB次声作用相同时间后，未见大鼠肾小管上皮细胞超微结构发生明显损伤，仅见肾小球毛细血管充血；经130dB次声作用14d后，大鼠部分肾小管上皮细胞发生坏死、脱落等病理改变，90dB次声作用相同时间后，可见肾小管上皮细胞溶酶体增生；经130dB次声作用21d后，大鼠肾小管上皮细胞线粒体明显被破坏，管腔内可见红细胞，肾球囊基膜出现复层化，90dB次声作用相同时间后，肾小管上皮细胞间隙扩大，间质血管扩张、充血，肾小管受压扭曲；当90dB、130dB次声分别作用28d及35d时，此时大鼠肾脏损伤程度有逐渐减轻的趋势。结论次声对大鼠多次作用后，可导致其肾脏发生直接的、广泛的、无组织特异性的损伤；当次声作用28d或更长时间后，大鼠肾脏组织各种细胞对次声的损伤作用具有一定的适应性。

The Ultrastructural changes of renal tissues following exposure to 90dB or 130dB infrasound of rats

Objective To investigate the ultrastructural changes of renal tissues following exposure to 90dB and 130dB infrasound(8Hz) of rats. Methods Seventy-eight male SD rats of grade II were randomly divided into 3 groups: control group (6), experiment group A (36) and experiment group B (36),each of the experiment groups had 6 subgroups according to the exposure time(1, 7, 14, 21 and 28 days) to the infrasound. The subgroups in experiment group A were exposed to 90 dB infrasound for 2 hours each day while the subgroups in group B were exposed to 130 dB infrasound for 2 hours each day. The sampled renal tissues were fixed with glutaraldehyde and Osmic acid. The ultrastructural changes were observed under the electron microscope. Results It was shown that the intercellular space increased and mitochondria slightly swelled in renal tubular epithelium in the 1 day subgroup expose to 130 dB infrasound. Congestion of intertubular capillaries was shown and the filtration membrane of renal corpuscle is normal. The ultrastructure of endothelium and podocytes as well as filtration membrane of renal corpuscle is normal in 1 day subgroup exposure to 90dB infrasound. Necrosis and shedding of a part of tubular epithelial cells were founded in renal tissues in 14 day group exposure to 130 dB infrasound. The lysosome hyperplasia of renal tubular epithelial cell was founded in 14-day group exposure to 90 dB infrasound. In 21-day group exposure to 130dB infrasound, necrosis of mitochondria in renal tubular epithelial cell was observed, some erythrocytes appeared in the tubule and irregular thickening of hypothallus were founded. The inflammatory infiltration and interstitial edema was shown and transfigure of renal tubule was found in 21-day group exposure to 90 dB infrasound. These damages were alleviated to some extent in 28 and 35 days post exposure to infrasound. Conclusion Exposure to infrasound can cause extensive and nospecific damage to renal cells of rat, adaptations of renal tissues to infrasound damage occure progressively after 28 days of exposure to infrasound.