【摘要】 目的研制专用于活体大鼠尺骨四点弯曲疲劳试验的夹具装置,制作活体微损伤动物模型,探讨活体大鼠疲劳试验方法并分析其骨生物力学性能。方法根据四点弯曲原理研制与PLD-5010型电子疲劳损伤试验机配套的夹具装置,该夹具由装载大鼠的载物盘和活体大鼠左(右)前肢加载装置2部分组成,后者包括上连接杆、弹簧上连接轴、线弹性弹簧、四点弯曲试验装置主体和下连接杆等零部件。选择4只12周龄雌性SD大鼠,随机分成对照组和负载组,每组各2只。2%戊巴比妥钠腹腔注射麻醉后,负载组大鼠用该夹具进行活体双侧尺骨四点弯曲疲劳损伤试验。负载频率:2 Hz,负载:10000次,负载力0.055 5 N/g(体重),隔天1次,共2次;对照组不行疲劳损伤试验。试验结束后处死2组大鼠,取双侧尺骨,用碱性品红染色,塑料包埋,磨片至50～80μm,Leica显微镜下发现骨微损伤后,用CCD头摄取图像并输入计算机储存。结果成功制作了疲劳夹具,可与骨电子疲劳损伤试验机配套应用。在负载组大鼠活体损伤的左右尺骨4个标本共20张磨片中均发现有微破裂,对照组未发现前述变化。结论该夹具适合于PLD-5010型电子疲劳损伤试验机,经过四点弯曲疲劳试验可初步建立活体大鼠尺骨微损伤模型,该活体大鼠疲劳试验方法可用于进一步的微损伤研究。更多还原

【Abstract】 Objective Try to establish a method of four-point bending fatigue testing in rat ulna and produce rat microdamage model in vivo.Methods According to four-point bending principle,we invented a fixture which can fit the PLD-5010 fatigue damage electronic testing machine.The fatigue fixture was composed of the loading plate for rats and left (right) forelimb loading test apparatus in vivo,the latter included the upper connecting rod,the upper linear elastic spring connecting shaft,the main four-point bending test device,the lower connecting rods and other components.Two- 12-week old SD female rats were anesthetized with 2%solution of sodium pentobarbital and subjected four-point bending fatigue damage test with bilateral ulna in vivo.The parameters were load frequency 2 Hz,10 000 times,the load force 0.055 5 N/g body weight,1 time/ every other day,total 2 times.The other two rats for the control and they did not suffer the fatigue loading.After the experiment,all rats were sacrificed.The left(right) ulna were taken for en-bloc basic fusin staining,routine plastic embedding,ground to 50 -80μm.The microdamage was found and analyses under the Leica microscope.Results The fatigue fixture was successfully made.Microcracks could be observed in total 20 grinding films of 4 left(right) injury ulna specimen in vivo.The microdamage could not be observed in the control group.Conclusion The fixture made by ourselves can be used in the PLD-5010 fatigue testing machine.With the fixture,the preliminary microdamage model by a four-point bending fatigue testing in rat ulna in vivo is established which can be used for further study of microdamage.更多还原