+Gz重复暴露后兔颈椎间盘BMP表达和影像学改变

Bone morphogenetic protein expression and imageological changes of intervertebral disc after repeated +Gz exposures in rabbits

目的:探讨+G z重复暴露对兔颈椎影像学和椎间盘骨形态发生蛋白(BMP)表达的影响。方法:15只兔随机分为对照组、+G z暴露1 d组、2周组、4周组、6周组,每组3只。+G z暴露组兔每天连续5次暴露于+6 G z、持续45 s,中间间歇5 m in。各组动物均于实验前后颈椎侧位拍片作自身对比,实验结束后气栓法处死并取颈椎做BMP免疫组化分析。结果:X线片显示对照组、+G z暴露1 d组及2周组兔颈椎无明显变化,而+G z暴露4周组和6周组兔颈椎均出现显著退行性改变。对照组、+G z暴露1 d、2周和4周组兔颈椎间盘未见BMP阳性细胞表达,+G z暴露6周组兔颈椎间盘的纤维环中可见少量散在分布的BMP阳性表达的软骨细胞。结论:+6 G z重复暴露4周和6周可引起兔颈椎发生退行性改变和椎间盘BMP的表达。

Objective： To explore the effect of different sustained time of ＋Gz exposure on imageological changes and bone morphogenetic protein （BMP） expression of the intervertebral disc in rabbits. Methods： Fifteen rabbits were randomly divided into five groups： control group, ＋6Gz/1d group, ＋6Gz/2 wk group, ＋6Gz/4 wk group and ＋6Gz/6 wk group. The rabbits in experiment groups were exposed to ＋6Gz/45s（5 times every day） for 1d, 2wk, 4wk and 6wk. Lateral cervical radiographies of each rabbit were studied by self - control method and the BMP expression of the cervical vertebrae was observed by light microscope with ABC immunohistochemical staining. Results： As compared with control, the X - ray film revealed that there were no changes of cervical vertebra in the rabbits of 1d and 2wk group, while the significant degenerative changes of intervertebral discs were observed in rabbits of 4 wk and 6 wk group after ＋6Gz exposure （P 〈 0.01）. There was no positive expression of BMP in the intervertebral disc in control group and 1 d, 2 wk, 4 wk group. A few chondrocytes of positive BMP expression were diffusedly distributed in some specimens of annular fibrosus 6 wk after ＋6Gz exposure. Conclusion： Repeated ＋6Gz exposures for 4 wk and 6 wk may induce degeneration of intervertebral disc in rabbits.