CAJ | 학술논문

目的：研究大鼠失坐骨神经后MyoD在腓肠肌中不同时相的表达变化，进一步探讨骨骼肌失神经后再生修复机制。方法将48只2月龄SD雄性大鼠随机分为八组，每组6只。其中正常对照和失神经各四组，于术后2、7、14、28 d取材，分别标记为Z1、Z2、Z3、Z4组和S1、S2、S3、S4组。在相应的时相内取各组大鼠左、右后肢的腓肠肌测肌湿重后冻存以备后续实验。计算各组腓肠肌湿重比及其肌腹段HE染色后的横截面积，Western blotting检测MyoD在腓肠肌的表达。结果手术组失神经侧（S1F右、S2F右、S3F右、S4F右）大鼠腓肠肌湿重逐渐减小，且各时相肌湿重比比较，差异均有统计学意义（P＜0.05）；HE染色后腓肠肌的各时相平均横截面积逐渐减小，即各时相组内与组间比较，差异均有统计学意义（P＜0.05）；Western blotting检测各时相失神经侧较正常对照组腓肠肌的MyoD表达增加，差异有统计学意义（P＜0.05）。结论大鼠腓肠肌失坐骨神经后第1周内出现明显肌萎缩现象，且萎缩速度在失神经前2周较快；MyoD蛋白在大鼠失坐骨神经后的表达增加，在失神经第2周时其表达量最高，随后开始降低，但仍高于正常大鼠。
목적：연구대서실좌골신경후MyoD재비장기중불동시상적표체변화，진일보탐토골격기실신경후재생수복궤제。방법장48지2월령SD웅성대서수궤분위팔조，매조6지。기중정상대조화실신경각사조，우술후2、7、14、28 d취재，분별표기위Z1、Z2、Z3、Z4조화S1、S2、S3、S4조。재상응적시상내취각조대서좌、우후지적비장기측기습중후동존이비후속실험。계산각조비장기습중비급기기복단HE염색후적횡절면적，Western blotting검측MyoD재비장기적표체。결과수술조실신경측（S1F우、S2F우、S3F우、S4F우）대서비장기습중축점감소，차각시상기습중비비교，차이균유통계학의의（P＜0.05）；HE염색후비장기적각시상평균횡절면적축점감소，즉각시상조내여조간비교，차이균유통계학의의（P＜0.05）；Western blotting검측각시상실신경측교정상대조조비장기적MyoD표체증가，차이유통계학의의（P＜0.05）。결론대서비장기실좌골신경후제1주내출현명현기위축현상，차위축속도재실신경전2주교쾌；MyoD단백재대서실좌골신경후적표체증가，재실신경제2주시기표체량최고，수후개시강저，단잉고우정상대서。
Objective To explore the expression changes of MyoD after losing the sciatic nerve in rats′gastrocnemius musle at different time phases in order to investigate the skeletal muscle regeneration and repair mechanisms after denervation further. Methods A total of 48 male SD rats aged 2-month-old were randomly divided into 8 groups,6 of each group including the 4 normal control groups and the 4 nerve-lost groups,obtaining the samples after 2,7,14,28 d respectively,marking group Z1, Z2,Z3,Z4 and group S1,S2,S3,S4. It was removed the gastrocnemius muscle from the latter legs of each group in the different time phases to measure their wet muscle weight and then frozed to prepare the following experiements. The wet weight ratio of the gas-trocnemius muscle and the cross-sectional area of musle belly setions stainied by HE. The expression of gastrocnemius muscle was detected by Western blotting. Results The wet musle weight was gradually decreased in the denervation side (S1Fright,S2Fright, S1Fright,S4Fright) from the operation groups. There were statistically significant compared the wet weight among the above time pahses (P<0.05). The average cross-sectional area after HE staining was declined at different time phases,whose difference had statisti cal significance within the group and among the groups(P<0.05). The denervation sides in various time phases were increased than the normal control groups in MyoD protein by Western blotting. The difference was statistically significant (P<0.05). Con-clusion The amyotrophy occurred within 1 week after loseing ischiadic nerve of rats′gastrocnemius muscle and accelerated in the first two weeks. The MyoD protein expression were increased after loseing their ischiadic nerve. The expression amount reach-es the peak at the second week of denervation ,then began to decrease but still higher than controls.