黄芪延缓大鼠失神经骨骼肌萎缩细胞凋亡机制研究

目的探讨黄芪对大鼠失神经早期骨骼肌细胞凋亡及凋亡相关蛋白活性的影响。方法 54只SD大鼠,♂,建立右下肢腓肠肌失神经支配模型,随机分为失神经对照组（n=18）,失神经黄芪干预组（n=18）和阴性对照组（n=18）。采用TUNEL技术和分光光度计检测术后2,14,28 d时大鼠腓肠肌骨骼肌细胞凋亡细胞核和凋亡相关蛋白Caspase-8,Caspase-9的活性,并结合肌肉湿重比分析其相关性。结果大鼠腓肠肌失神经支配后凋亡增加（P〈0.05）。失神经后14 d和28 d黄芪干预组腓肠肌湿重比高于同期失神经对照组（P〈0.05）,而其凋亡细胞核以及Caspase-8,Caspase-9的活性则低于相应失神经对照组（P〈0.05）。结论黄芪可以有效延缓去神经早期骨骼肌的萎缩,其作用机制与抑制骨骼肌细胞凋亡有关。

Protective Effects of Astragali Radix on Cell Apoptosis in Denervated Skeletal Muscle in Rat

OBJECTIVE To study the influence of Astragali Radix upon apoptosis in denervated skeletal muscle atrophy at the early stage of peripheral never injury in rats. METHODS 54 male SD rats were randomized into 3 groups. In positive control group, the sciatic nerve was transected and prevented form regenerating. In experimental model group, the sciatic nerve were transected, and Astragali Radix was performed. In negative control group, the gastrocnemius were removed 2, 14 and 28 days later. Muscle-wet weight (GAS) and body mass (BM) are weighed. The ratio of muscle wet weight served as the degree of muscle atrophy. A search for marker of apoptosis, nuclear DNA fragmentation, using terminal deoxyribonucleotidyl transferase mediated dUTP nick end labeling (the TUNEL medthod) in situ. Another portion of gastrocnemius muscle was homogenized and then analysed the activity of caspase-8 and caspase-9 by spectrophotometry. RESULTS The experimental model group had a higher ratio of muscle wet weight comparing with positive control group at the same time points(P<0.05). TUNEL labeling of fragmented DNA on histological sections in experimental model group revealed higher levels of apoptotic nuclei than negative control group, but lower than positive control group at the early stage(P<0.05). The activity of caspase-8 and caspase-9 in experimental model group is also higher than positive control group, lower than negative control group (P<0.05). CONCLUSION Astragali Radix can significantly retard denervated skeletal muscle atrophy at the initial stage of peripheral never injury in rat and has protective effect on skeletal muscle cell apoptosis after peripheral never injury in rats.