大鼠尸僵发展过程中肌节长度的变化及其长度测定

目的观察大鼠尸僵发展过程中肌节形态、肌节长度的变化。方法 2 1只大鼠分为 3组 ,每组大鼠分别于死后立即和死后 2h、 4h、 6h、 8h、 12h、 2 4h取材 ,扫描电镜下观察大鼠死后不同时间的肌节形态 ,同时测定肌节长度。结果死后立即取材标本肌原纤维松散 ,纤维间有一定的间隙 ;死后 2h ,肌原纤维间界限模糊 ,出现周期性横纹 ;死后 4h、 6h横纹清晰 ;死后 12h肌原纤维断裂 ,仍可见横纹 ;死后 2 4h肌原纤维断裂、融合。各组大鼠肌节长度与同组立即取材时比较 ,死后 2h、 4h、 6h、 8h均显著变短 (P值均小于 0 0 0 1) ,其中死后 4～ 6h最短 ;死后12h均无显著性差异 (P值均大于 0 0 5 ) ;死后 2 4h ,组 1、组 3无显著性差异 (P值均大于 0 0 5 ) ,组 2差异显著(P值为 0 0 0 7)。结论用扫描电镜测定肌节长度 ,发现肌节长度随尸僵经过时间的延长而发生变化

An experimental study on the length change of the sarcomere in rat during the rigor mortis

Objective The purpose of this study is to observe the length change of the rats sarcomere during the rigor mortis.Method Twenty one rats were divided into three groups and samples were taken immediately after death,2h,4h,6h,8h,12h,24h,postmortem(p.m.).The sarcomeres of 21 rats at various postmortem intervals were measured under the scanning electron microscope(SEM).Results Morphologically,the myofibrils of samples taken immediately after death were loose and separate each other.At 2h p.m.,the borders between the myofibrils were blurred and periodical"striations"appeared.At 4h p.m.,and 6h p.m.,the striations of the muscles fibers became apparent.At 12h p.m.,myofibrils were broken,but striations still could been seen.At 24h p.m.myofibrils were broken and melted.Compared with the length of sarcomeres sampled immediately after death,the length of the myofibrils were significant short at 2?4?6?8h p.m.in three groups( P <0 001),but at 12h p.m.,there was no significant difference in three groups( P >0 05);At 24h p.m.there was no significant difference in the first and third group( P >0 05),while in the second group there was significant difference( P <0 01).Conclusion The length of the sarcomere was changing along with the time elapsed after death during the rigor mortis.