实验大鼠斜方肌肌纤维型组成及分布研究

目的探讨大鼠斜方肌的肌纤维型组成和分布,借以了解该肌功能。方法取成年SD大鼠斜方肌升部肌组织进行冰冻切片(8μm厚),采用Guth-Samaha肌球蛋白ATP酶组织化学染色法并稍做改良,对其进行肌纤维分型研究。结果SD大鼠斜方肌经肌球蛋白ATP酶组织化学染色后可明确分出2种肌纤维型,即白色的Ⅰ型纤维(慢缩纤维)和深褐色的Ⅱ型纤维(快缩纤维),2种肌纤维在肌内呈棋盘样均匀分布;图像分析计数其Ⅰ型纤维占(48.8±6.9)%,Ⅱ型纤维比例为(51.2±6.9)%,2者比较差异无统计学意义(P>0.05)。结论SD大鼠斜方肌2型肌纤维所占比例均等,与其维持颈背部姿势的作用一致。

Composition and Distribution of Muscle Fiber Types of Rat Trapezius Muscle

Objective To investigate the composition and distribution of fiber types of SD rat trapezius muscle and evaluate the muscle function.Methods The ascending portion of trapezius muscles from both sides of 10 adult SD rats was studies.8-μm thick eryostat sections were cut and then stained with the myosin-ATPase by Guth & Samaha following a procesure modified partially.Results Trapezius muscles of SD rats can be,clearly identified as typeⅠ(slow twitch oxidative fibers,SO)and typeⅡ(fast twitch glycolytic fibers,FG),the former looks brightly while the latter darkly.The distribution pattern of this two types of muscle fibers is uniform and chessboard-like.The percentage of typeⅠfibers was(48.8±6.9)%, much the same as the typeⅡfibers(51.2±6.9)%(P>0.05).Conclusion Two types of fibers with the half ratio in ascending portion of SD rat trapezius implies that rat trapezius muscle participates more in postures maintenance of head and upper hind neck.