Suzuki A, Tsuchiya T, Ohwada S, Tamate H
Laboratory of Animal Morphology, Faculty of Agriculture, Tohoku University, Sendai 980, Japan.
J Morphol. 1985 Aug;185(2):145-154. doi: 10.1002/jmor.1051850202.
The composition of myofiber types varies within thigh muscles of chickens. The present study was designed to determine whether or not myofiber types were distributed uniformly across the diameter of the thigh muscles of chickens. Cross sections from middle portions of muscles were used histochemically to examine differences in distribution and composition of myofiber types in the muscles. Myofibers that reacted moderately (M) or strongly (S) for myosin adenosine triphosphatase (ATPase) after preincubation at pH 4.3 were classified as type I. Type I myofibers reacted weakly (W), moderately (M), or strongly (S) for ATPase after preincubation at pH 10.6; these type I myofibers were subclassified into four types (I , I , I , and I ). Myofibers that reacted negatively for acid-stable ATPase and strongly for alkali-stable ATPase were classified into two types: type IIA, with strong NADH tetrazolium reductase (NADH-TR), and type IIB, with weak NADH-TR activity. The M. pubo-ischio-femoralis pars lateralis had numerous type IIA myofibers and very few type I myofibers, whereas the pars medialis had many type I myofibers and few type I and IIA myofibers. The type I group of myofibers did not exceed about 50% in the other muscles, which had one to three types of type I , I , and I myofibers. The Mm. femorotibiales had more type I , and I myofibers in the deep regions near the femur than in the superficial regions. The M. iliotibialis cranialis, M. iliofibularis, and M. flexor cruris medialis had more type I , I , or I myofibers in the medial regions than in the lateral regions. A few type I myofibers were scattered in the cranial part of M. iliotibialis and in the M. ambiens. The M. flexor cruris lateralis pars pelvica had type IIA and IIB myofibers exclusively. All the muscles had type IIA myofibers. Type IIB myofibers existed in the muscles except the M. puboischio-femoralis. Type IIA and IIB myofibers differed in proportion in different muscles and in their different regions. The type I group of myofibers was generally concentrated more in the deep regions near the femur and in the medial regions than in the superficial and lateral regions of the thigh muscles. The distribution of type IIA myofibers resembled that of type I group. Type IIB myofibers showed a distribution opposite to that of type I group and IIA myofibers. The spatial distribution of myofiber types within individual muscles can account for the various locomotory and postural requirements of the thigh.
鸡大腿肌肉中肌纤维类型的组成存在差异。本研究旨在确定肌纤维类型在鸡大腿肌肉直径上的分布是否均匀。采用肌肉中部的横切面进行组织化学分析，以研究肌肉中肌纤维类型的分布和组成差异。在pH 4.3预孵育后，对肌球蛋白三磷酸腺苷酶（ATPase）反应中等（M）或强烈（S）的肌纤维被归类为I型。I型肌纤维在pH 10.6预孵育后对ATPase反应弱（W）、中等（M）或强烈（S）；这些I型肌纤维被细分为四种类型（I、I、I和I）。对酸稳定ATPase反应阴性而对碱稳定ATPase反应强烈的肌纤维分为两种类型：IIA型，具有强烈的NADH四氮唑还原酶（NADH-TR）活性；IIB型，具有较弱的NADH-TR活性。耻骨坐骨股肌外侧部有大量IIA型肌纤维，I型肌纤维极少，而内侧部有许多I型肌纤维，I型和IIA型肌纤维较少。在其他肌肉中，I型肌纤维组不超过约50%，这些肌肉有一到三种I、I和I型肌纤维。股胫肌在靠近股骨的深部区域比浅表区域有更多的I和I型肌纤维。髂胫肌前部、髂腓肌和股内侧屈肌在内侧区域比外侧区域有更多的I、I或I型肌纤维。少数I型肌纤维散在于髂胫肌的头部和缓行肌中。耻骨坐骨股肌骨盆部外侧只有IIA型和IIB型肌纤维。所有肌肉都有IIA型肌纤维。除耻骨坐骨股肌外，其他肌肉中均存在IIB型肌纤维。IIA型和IIB型肌纤维在不同肌肉及其不同区域的比例不同。I型肌纤维组通常更多地集中在靠近股骨的深部区域和内侧区域，而不是大腿肌肉的浅表和外侧区域。IIA型肌纤维的分布与I型肌纤维组相似。IIB型肌纤维的分布与I型肌纤维组和IIA型肌纤维相反。单个肌肉内肌纤维类型的空间分布可以解释大腿的各种运动和姿势需求。
