氨基酸维生素对力竭游泳大鼠骨胳肌超微结构及相关酶的影响

Effects of amino acids and vitamins on the ultrastructure of the skeletal muscle and related enzymes in swimming-exhausted rats

目的探讨氨基酸维生素制剂对力竭游泳大鼠腓肠肌超微结构、钙依赖蛋白酶(calpains)、泛素(ubiquitin)及一氧化氮合酶(nitricoxide synthase,NOS)的影响。方法采用数字表法,将经适应性游泳后的36只雄性SD大鼠,随机分为复方氨基酸胶囊组(胶囊组)、空白对照组(对照组)和氨基酸果糖粉固体饮料组(冲剂组),采用无负重游泳方式建立大鼠力竭游泳模型。分别给予复方氨基酸胶囊、正常饮用水和氨基酸果糖饮料配方饮水14 d,末次游泳力竭结束后处死大鼠,电镜观察大鼠腓肠肌超微结构,ELISA法检测大鼠腓肠组织中calpain-1、calpain-2、ubiquitin和NOS水平。结果胶囊组和冲剂组肌细胞胞质内线粒体和肌丝结构基本完整,对照组细胞明显肿胀变性,线粒体可见不同程度损伤,伴有膜、嵴松散、弯曲、溶解、断裂现象,甚至出现空泡化。胶囊组和冲剂组大鼠腓肠肌组织中calpain-1、calpain-2和ubiquitin均明显低于对照组(P<0.05),NOS则低于对照组(P<0.05)。结论补充复方氨基酸维生素制剂可通过减轻腓肠肌超微结构改变,调节肌肉损伤相关酶来提高机体抗疲劳能力。

Objective To observe the effects of amino acids and vitamins on the ultrastructure of the calf skeletal muscle and related enzymes, such as calpain-1, calpain-2, ubiquitin and nitricoxide synthase （NOS） in swimming-exhausted rats. Methods Following preconditioned swimming exercise, 36 male SD rats were randomly divided into 3 groups： the compound amino acid capsule group, the blank control group and the amino acid granule group. The swimming-exhausted model was developed with load free swim- ming. The 3 groups were respectively treated with amino acids capsules, normal drinking water and amino acid-fructose granule beverage for 14 days. Following termination of the last exhausted swimming, the ultrastructure of the calf skeletal muscle was observed under electron microscopy. The levels of calpain-1, calpain-2, ubiquitin and NOS in the skeletal muscle were detected with ELISA. Results The uhrastructures of chondriosome and myofilament in the skeletal muscle for the capsule group and the granule group were fundamental integral, while those of the control group were obviously swelling and denatured. Lesion of chondriosome to a more or less extent could be noted, accompanied with slackness, solution and rupture or even cavitation in membrane and crista. Compared with those of the con- trol group, the levels of calpain-1, calpain-2, ubiquitin in the skeletal muscle of both the capsule and the granule groups were signifi- cantly lower （ P 〈 0. 05 ）, and the levels of NOS were significantly lower than that of the control group （ P 〈 0. 05 ）. Conclusion Supplementation of amino acids and vitamins could improve resistance to fatigue through alleviation of the changes in the uhrastructure of the calf skeletal muscle and regulation of enzymes related with muscle injury.