高原低压低氧环境对大鼠骨形态和微结构的影响研究

Effects of chronic hypobaric hypoxia on bone morphology and microstructure in rats

目的:研究长期暴露在高原低压低氧环境下大鼠骨形态和微结构的变化,探讨低压低氧环境对大鼠骨骼发育的影响。方法:将16只10周龄的SD大鼠按照体质量随机分为对照组和低压低氧组,每组8只。低压低氧组大鼠每天在低压低氧模拟氧舱中处理22 h,连续处理6周;对照组放置在正常大气压下,不作其他处理。实验过程中实时监测并记录大鼠的进食、体质量。使用游标卡尺测量右侧股骨长度;采用Micro-CT扫描测定大鼠右侧股骨远端干骺端皮质骨和骨小梁的微结构;计算骨组织的骨体积分数(BV/TV)、骨小梁数量(Tb.N)、骨小梁厚度(Tb.Th)和骨小梁的分离度(Tb.Sp)。使用SPSS 22.0软件进行统计学分析。结果:低压低氧处理2周到实验结束,低压低氧组大鼠的体质量始终小于对照组(P<0.05);低压低氧处理1周到实验结束,低压低氧组大鼠的进食量始终少于对照组(P<0.05);低压低氧组大鼠股骨长度及BV/TV、Tb.N、Tb.Th均显著小于对照组(P均<0.01),Tb.Sp大于对照组(P<0.01)。Micro-CT三维重建结果显示低压低氧组骨小梁的微结构受损,骨量明显降低,空间排列疏松、空隙较大,而对照组骨小梁骨量正常,空隙较小且均匀。结论:长期暴露于低压低氧环境下会损害机体的健康,影响骨骼的生长发育,造成骨骼功能障碍。

Objective To study bone morphology and microstructure in rats exposed to high altitude for a long time,and to explore the effects of hypobaric hypoxia conditions on bone development in rats.Methods Sixteen 10-week-old SD rats were randomly divided into a control group and a hypobaric hypoxia group(experiment group)according to their body mass,with 8 rats in each group.The rats in the experiment group were treated with hypobaric hypoxia in a simulated oxygen chamber for 22 h per day for 6 weeks;the rats in the control group were placed under normal atmospheric pressure without other treatment.The rats'food intake and body mass were monitored and recorded in real time during the experiment.The length of the right femur was measured using vernier calipers;the microstructure of the cortical bone and trabecular bone of the right distal femoral epiphysis was determined by Micro-CT scanning;such indexes were calculated as the bone volume fraction of bone tissue(BV/TV),the number of trabecular bone(Tb.N),the thickness of trabecular bone(Tb.Th)and the separation of trabecular bone(Tb.Sp).Statistical analysis was carried out using SPSS 22.0 software.Results The body mass of the rats in the experiment group was always smaller than those in the control group after 2 weeks of hypobaric hypoxia treatment until the end of the experiment(P<0.05);the rats in the experiment group always ate less than those in the control group after 1 week of hypobaric hypoxia treatment until the end of the experiment(P<0.05);the femur length and BV/TV,Tb.N,Tb.Th in the experiment group were significantly lower than those in the control group(P<0.01),while the Tb.Sp was greater than that in the control group(P<0.01).Micro-CT 3D reconstruction showed that the experiment group had impaired microstructure of trabecular bone,with significantly lowered bone volume,loose arrangement and large voids,while the trabecular bone in the control group had normal bone volume and small and uniform voids.Conclusion Long-term exposure to hypobaric hypoxia environments can damage the health of the body,affect bone growth and development and cause bone dysfunction.[Chinese Medical Equipment Journal,2022,43(7):6-9,22]