模拟失重雌、雄性大鼠背根神经节微观结构变化比较研究

Comparative Study on Microstructural Changes of Dorsal Root Gsnglia in Female and Male Simulated Weightlessness Rats

目的研究尾吊模拟失重对雌、雄性大鼠第5腰椎背根神经节(dorsal root ganglion,DRG)微观结构的影响。方法成年雌、雄性大鼠各20只,按性别和是否模拟失重随机分为4组。实验组尾部悬吊建模。4周后取第5腰椎双侧DRG,HE和甲苯胺蓝染色观察细胞和尼氏体形态,电镜观测髓鞘板层结构,免疫组化检测髓鞘碱性蛋白(myelin basic protein,MBP)含量。结果模拟失重组DRG细胞间隙轻度增宽,部分节细胞与卫星细胞分离;尼氏体结构蓬松、肿胀,染色不均匀。电镜下模拟失重组髓鞘板层结构紊乱、松散;免疫组化结果显示,尾吊组MBP染色减轻,积分光密度(integral optical density,IOD)值较对照组降低(P<0.01);不同性别间差异显著(P<0.05)。结论模拟失重导致背根神经节细胞、细胞器及MBP的改变,雌性组DRG的损伤较雄性组更严重,提示航天医疗应个性化对待此种差异。

Objective To study the microstructural changes of dorsal root ganglia （DRG） in female and male simulated weightlessness rats. Methods Twenty male and twenty female 3- month old SD rats were selected. According to their gender, they were randomly divided into 4 groups, 2 experimental groups （simulated weightlessness with hindlimbs unloaded） and 2 control groups. After 4 weeks, both side LS-DRG were taken out. Cell morphology with HE staining, Nissl body shape with toluidine blue staining, DRG lamellar structure of myelin with electron microscopy and immune-histo-chemical for MBP content were observed. Results The gaps between DRG cells were widened slightly, ganglion cells and satellite cells were separated partly in hind- limb unloaded groups. Nissl body structure became fluffy, swelling, dyeing uneven, and the structural vari- ants were larger in hindlimb unloaded group than control. Lamellar structure of myelin showed disorder and degenerative changes significantly with electron microscope in hindlimb unloaed groups. Immuno-histo-chemis- try showed that in the unloaded groups, the integral optical density （IOD） value of MBP decreased （P 〈 0. 01 ） significantly compared with the control groups. These differences between female and male hindlimb un- loaded groups were more significant（ P 〈 0.05 ）. Conclusions Simulated weightlessness for 4 weeks can in- duce serious changes in DRG cells, organelles and myelin basic protein, dorsal root ganglion injury male group is more serious than that in the male group. For such differences, aerospace and medical should be individualized. in the fe- treatment