次声对大鼠胃窦粘膜形态学的影响

The effects of infrasound on the morphology of the gastric mucosa

目的探讨不同频率和声压级水平的次声对大鼠胃窦粘膜形态学的影响。方法共选取210只雄性SD大鼠,将其中140只随机分为对照A组、8 Hz-90 dB组、8 Hz-130 dB组及16 Hz-130 dB组,每组35只。各次声组大鼠按设计要求分别暴露于不同频率和强度的次声舱内,每天2 h；对照A组大鼠则置于次声舱内,每天2 h,期间无次声作用。每组于次声作用第1,7,14,21及28天时各随机取出7只大鼠,采用HE染色及电子显微镜观察其胃窦粘膜病理改变情况。另外70只大鼠则随机分为暴露组及对照B组,每组各35只。将暴露组大鼠置于次声舱内,次声参数为8 Hz、130 dB,每天作用2 h,持续14 d后停止；对照B组大鼠亦每日置于次声舱中2 h,期间无次声作用。2组大鼠分别于次声作用结束后第1,7,14,21及28天时各随机取出7只大鼠进行上述指标检测。结果①8 Hz、90 dB次声作用1 d后,大鼠胃窦粘膜损伤积分与对照A组间差异无统计学意义(P＞0．05)；作用7,14,21及28 d后则明显高于对照A组(P＜0．01)。8 Hz、130 dB及16 Hz、130 dB次声作用1,7,14,21及28 d后,大鼠胃窦粘膜损伤积分均明显高于对照A组(P＜0．01)。②8 Hz、130 dB次声作用1,7,14,21及28 d时,其胃窦粘膜损伤积分均明显高于8 Hz-90 dB组(P＜0．01)；作用14,21及28 d时,则明显高于16 Hz-130 dB组(P＜0．01)。③8 Hz、130 dB次声连续作用14 d后,发现大鼠胃窦粘膜损伤积分随后逐渐下降,但在次声作用停止后1,7,14,21及28 d时仍显著高于对照B组(P＜0．05～0．01)。④8 Hz及16 Hz次声可引起大鼠胃窦牯膜细胞线粒体和内质网等超微结构发生异常改变。结论8 Hz、90 dB或8 Hz、130 dB或16 Hz、130 dB次声作用均可引起大鼠胃窦粘膜损伤,其严重程度与次声频率、强度及作用时间等密切相关；大鼠经次声多次作用后可产生一定的适应性,当次声作用停止后,其胃窦粘膜损伤有自我恢复趋势。

Objective To observe the effects of infrasound （IS） of different frequencies and intensities on the pathological morphology of the gastric mucosa （GM） in rats. Methods One hundred and forty male Sprague- Dawley rats were randomly and evenly divided into a control group （group A） , an 8 Hz 90 dB group （group B） , an 8 Hz 130 dB group （group C） and a 16 Hz 130 dB group （group D）. IS with these frequencies and intensities was administered daily for 2 h to all groups except group A, which received sham infrasound. The other 70 rats were randomly and evenly divided into a second control group （group E） and an exposure group （group F） , in which the rats were continuously stimulated by IS at 8 Hz and 130 dB for 2 h a day for 14 d. The pathological morphology of the GM in each group was observed at 1 d, 7 d, 14 d, 21 d and 28 d after IS exposure. Results ①Compared with group A, GM lesion scores were significantly increased in groups B, C and D at 1 d, 7 d, 14 d, 21 d and 28 d （P 〈 0.01） , but not in group B at 1 d. ② Compared with group B, the GM lesion scores in group C were obviously increased at 1 d, 7 d, 14 d, 21 d and 28 d, while scores were also obviously improved in group C in comparison with those in group D at 14 d, 21 d and 28 d （P 〈0.01 ）.③The GM lesion scores in group F decreased gradually after IS, but were still higher than those in group E at 1 d, 7 d, 14 d, 21 d and 28 d after IS. ④The ultrastructures of the chondrosome and endocytoplasmic reticulum in GM cells were deformed after 8 Hz and 16 Hz IS. Conclusion 8 Hz 90 dB, 8 Hz 130 dB and 16 Hz 130 dB IS can all result in GM damage in rats. The injury severity was closely related to the frequency, intensity and duration of the IS. Rats can adapt to IS after several exposures, and the damage tends to recover automatically.