不同制动时相兔骨骼肌萎缩与细胞凋亡的实验研究-原位缺口末端标记法(TUNEL)的观察检测

探讨制动后骨骼肌萎缩的发生机制与骨骼肌细胞凋亡的关系。按照 Sievanen法制备不同时相的制动实验组 ,2 4只实验兔随机分为 4组 ,每组 6只 ,实验侧用管形石膏固定 ,自身未固定侧做对照组。在制动后 3、7、14和 2 8d取材 ,应用末端转移酶介导的 U TP缺口末端标记法 (Td T— mediated d UTP nick end labeling,TUNEL )检测萎缩骨骼肌中有无凋亡的骨骼肌细胞 ,并与形态学的观察结果相对照。对各组的数据进行统计学处理。结果表明不同制动时相所致的萎缩骨骼肌中均可发现有程度不一的骨骼肌细胞发生凋亡 ,以 14 d组最为显著。不同时相凋亡的肌细胞在空间的分布上呈不一致性。制动所致萎缩的骨骼肌中有时可见呈假阳性 TU NEL染色 ,但与凋亡的肌细胞的表现是不同的。我们认为 (1)制动后骨骼肌萎缩有骨骼肌细胞凋亡的参与。 (2 )骨骼肌细胞凋亡的多少与制动时相密切相关 ,以制动后 14 d最为明显。 (3)凋亡的骨骼肌细胞在空间分布上随制动时相不同而不同 ,呈不一致性。 (4 )制动后骨骼肌萎缩的程度与肌细胞凋亡的程度密切相关。

Cell Apoptosis in Atrophic Skeletal Muscle Induced by Immoblization in Rabbits--An Experimental Study Using TUNEL

This experiment was designed to explore the correlation between the mechanism of immobilization-induced skeletal muscle atrophy and the apoptosis of muscular cells. The models of skeletal muscle atrophy induced by immobilization for different length of time were established according to Sievanen II methods. 24 rabbits,each of them having one hind leg fixed by the tubal plaster and the other one free as control,were randomly divided into four groups depending on time of fixation (3,7,14,and 28 days respectively).The animals were sacrificed by the end of fixation. TdT-mediated d-UTP nick end labeling (TUNEL) was used to investigate the apoptotic muscle cells in the animal's bone. By comparing the apoptotic muscle cells with the morphology of the skeletal muscle,the correlation between cell apoptosis and skeletal muscle atrophy were analyzed. Apoptotic muscle cells did appear after immobilization in the atrophied skeletal muscle. In various groups,some cells with false positive stained TUNEL were found in the atrophic muscle,which could be distinguished from apoptotic cells by their characteristics.In conclusion,cell apoptosis participates in the process of skeletal muscle atrophy induced by immobilization;the amount of apoptotic cells is strongly associated with the time of immobilization,its peak appears on the 14 th day of immobilization;the distribution of apoptotic skeletal muscle cell varies with the time of fixation. The severity of skeletal muscle atrophy is associated with the degree of the muscle cell apoptosis.