【摘要】 研究分析了家兔、大鼠腓肠肌在生后各年龄阶段的内侧头、外侧头的内侧亚体、中间亚体或外侧浅亚体、外侧亚体或外侧深亚体内快慢肌纤维的发育情况 ,应用大体解剖结合组织化学方法确定了其肌亚体 ,并进行琥珀酸脱氢酶染色、图像分析两型肌纤维的直径特征 ,以及肌构筑学与肌诱发电位的测量。结果表明 :家兔在生后 1个月时 ,内侧亚体从其深面凸现于内侧头与外侧亚体之间 ,中间亚体居于内侧亚体远端 ;大鼠内侧头未能区分肌亚体 ,其外侧头分为内侧亚体、外侧浅亚体 ,而外侧深亚体居于外侧浅亚体的深面呈重叠状 ;生后2、 3天均未能分出Ⅰ、Ⅱ型肌纤维 ,也未见有原始肌束 ;Ⅰ、Ⅱ型肌纤维比例随年龄增长而变化 ,内侧亚体的Ⅱ型肌纤维比例在家兔与大鼠的生后发育中始终占优 ,而在其它各肌亚体内 ,Ⅱ型肌纤维的比例在发育中不恒定 ,直至成年后Ⅱ型肌纤维才趋于稳定并占优。在生长发育过程中 ,各肌亚体内Ⅱ型肌纤维的直径在各年龄段均大于Ⅰ型肌纤维。生后 6个月家兔外侧头内侧亚体 (FL/CSA)比值越大 ,倾向于速度型构筑 ;内侧头、中间亚体和外侧亚体 (CSA/MW )比值越大 ,倾向于力量型构筑。大鼠腓肠肌外侧头内侧亚体乙酰胆碱酯酶染色显示葡萄状运动神经末梢支配慢肌纤维 ,斑点状运动终板位于快肌纤维更多还原

【Abstract】 The development of fast twitch and slow twitch fibers in the medial gastrocnemius,the medial subvolume,the intermediate subvolume or the lateral superficial subvolume,the lateral subvolume,or the lateral profound subvolume of the lateral gastrocnemius of rabbits and rats at different postnatal ages were analysed and studied.Gross anatomical and histochemical methods were used to determine the muscular subvolume.Succinate dehydrogenase(SDH) staining,image analysis of the diameters of the two fiber types,the architecture index and the muscle evoked potential were measured.The results indicate that the medial subvolumes of rabbits at 1 month age protruded between the medial gastrocnemius and the lateral subvolume,the intermediate subvolumes occupied the distal end of the medial subvolumes.The subvolumes of the medial gastrocnemius were distinguished into the medial subvolume,the lateral superficial subvolume; the lateral profound subvolumes were the deep part of the lateral superficial subvolume.Ⅰ,Ⅱ fiber types and the original fasciculi were not distinguished within three days after birth.The proportions of the types Ⅰ and Ⅱ fiber changed with age.The proportion of typeⅡ fiber in the medial subvolume took precedence in the postnatal development of rabbits and rats.The proportion of typeⅡ fiber in the other subvolumes were not permanent during postnatal development,and also tended towards stability in adults.The postnatal diameters of the typeⅡfiber were larger than typeⅠfibers in every subvolume.The ratio of fiber length/cross sectional area of the medial subvolume was larger and designed for velocity in six months old rabbits.The ratio of cross sectional area/muscle weight of the medial gastrocnemius,the intermediate and the lateral subvolume were larger and designed for strength.There were grapelike motor endings in slow fibers and spot motor end plates in the fast fibers at Acetylthiocholine strarase(AchE) stain of the medial subvolume of lateral gastrocnemius in rats.更多还原