模拟失重和噪声复合因素对豚鼠内耳淋巴液容积的影响

摘要

Objective To investigate the effects of simulated weightlessness and noise on inner ear volume in guinea pigs. Methods Twenty-four healthy guinea pigs were randomly divided into a noise exposure group (n=12), a simulated weightlessness group (n=6) and a weightlessness plus noise exposure group (n=6). Weightlessness was simulated by posterior limb suspension with a -30° angle between horizon and longitudinal axis of the body. Noise exposure was at 72 ± 2 dB SPL. Auditory brainstem response (ABR) thresholds were acquired and the volume of the inner ear was assessed by MRI before, at the end of and 3 days after the experiment respectively. Results In the noise exposure group, the inner ear volume showed little change when compared between before and 3 days after exposure (P> 0.05). In the weightlessness group, the inner ear volume showed an increase at the end of the experiment, comparing with before the experiment (P<0.05), although the volume was similar when compared between before and 3 days after the experiment (P > 0.05). When weightlessness was combined with noise exposure, not only the inner ear volume was increased at the end of the experiment, it remained increased 3 days after, as compared with before the experiment (P<0.05). The volume showed little change 3 days after the experiment compared to immediately after the experiment in this group (P>0.05). Conclusion Short-term simulated weightlessness can increase the inner ear volume in guinea pigs. The change appears to recover in about 3 days, but not so when the simulated weightlessness is combined with noise exposure%目的 探讨模拟失重和噪声复合因素对豚鼠内耳淋巴液容积的影响.方法 健康豚鼠24只随机分为单纯失重组12只、单纯噪声组6只、失重+噪声组6只,分别测试实验前、实验5天及实验结束后3天听性脑干诱发电位(ABR)阈值及内耳MRI扫描,并用自制专用软件对内耳淋巴液容积进行计算.结果 单纯噪声组实验前后内耳容积无差异(P＞0.05)；单纯失重组实验5天与实验前、实验结束后3天与实验5天相比有显著性差异(P＜0.01),实验结束后3天与实验前相比无明显差异(P＞0.05)；失重+稳态噪声组实验5天及实验结束后3天豚鼠内耳容积较实验前明显增大(P＜ 0.01),实验5天与实验结束后3天豚鼠内耳容积无显著差异(P＞0.05).结论 失重环境可使豚鼠内耳淋巴液容积变大,但是短期单纯失重环境豚鼠内耳淋巴液容积变化可恢复,失重加噪声复合因素会加重内耳淋巴液容积变化,且实验后3天后内耳淋巴液容积无恢复.