模拟失重对大鼠下颌骨、腰椎和股骨组织结构的影响

目的了解模拟失重对大鼠不同部位骨骼组织结构的影响。方法25只大鼠,随机分为2组:对照组(n=10)和头低位30°尾吊组(n=15)。实验第28天时,取2组动物的下颌骨、腰椎和股骨。观察指标为下颌骨髁状突、下颌骨体磨牙区和前磨牙区、第一腰椎、股骨头、股骨中段和股骨髁部的组织学结构。结果对照组和尾吊组髁状突骨形态学结构无明显差别,只是尾吊组骨小梁之间的交织程度增加。2组下颌骨体部骨质均较致密,骨质结构、牙周膜厚度无明显差别。与对照组比,尾吊组前磨牙区骨板排列规则,成熟程度比磨牙区高;尾吊组磨牙区骨增生线排列紊乱不规则,示骨质改建较多。与对照组比,尾吊组股骨、腰椎骨小梁成分减少,粗细不均匀,小梁之间交织连接程度差。结论4周模拟失重可以引起脊椎骨股骨的骨质疏松,但是对下颌骨没有明显的影响。

Effects of Simulated Weightlessness on Rats Mandible,Lumbar Vertebra and Femur

Objective To observe the effect of weightlessness simulation on rats mandible, lumbar vertebra and femur. Method Twenty five Wistar rats were randomly arranged into control group(n=10) and tail-suspendsion group(n=15 rats). The experiment lasted for 28 d. Then the mandible, lumbar vertebra and femur were excised and the histological structure of condylar process of mandible, molar and premolar area of mandible body, first lumbar, head, middle segment and condyle of femur were examined. Result After tail-suspension there was no distinct change in bone density and bone mass of condylar process. But the degree of interlacement of trabecular bone increased. The bone substance of mandible was very dense in both control and experimental groups. There was no stimulated difference of bone structure and bone mass between the two groups. There was no marked change in the thickness of periodotal membrane. The bone lamella in premolar area of experimental group arranged regularly. And its maturity was higher than that in molar area. The line of bone hyperplasia in molar area of experimental group arranged disorderly and irregularly, which means that much bone remodeling occurred. The component of trabecular bone decreased in femur and lumbar vertebra and the thickness was uneven. The interlacement and connection among trabecular bones was poor. Conclusion Four weeks of stimulated weightlessness can lead to osteoporosis in acantha and feurar but has no distinct effect on mandible.