Vita G F, Mastaglia F L, Johnson M A
Neuropathol Appl Neurobiol. 1980 Nov-Dec;6(6):449-63. doi: 10.1111/j.1365-2990.1980.tb00222.x.
The histochemical fibre type composition of the rat superior and medial rectus (SR and MR), superior oblique (SO) and levator palpebrae superioris (LPS) muscles was studied using the myofibrillar ATPase and NADH-tetrazolium reductase (NADH-TR) techniques. In the SR, MR and SO a peripheral zone containing small fibres and a central zone containing both small and large fibres could be identified. Four fibre types were present in the central zone of these muscles and were categorised as Type 1, Type 2a. Type 2a'. and Type 2b. Four fibre types were also identified in the peripheral zone--Type 1, Type 2a, Type 2a' and Type 2c. In the LPS Type 1, Type 2, Type 2a', Type 2b and Type 2c fibres were evenly intermixed without a zonal arrangement. The Type 1, Type 2a, Type 2b and Type 2c fibres correspond to accepted fibres types in the rat limb muscles. The type 2a' and Type 2a" fibres were differentiated from the Type 2a fibres on the basis of size and pattern and intensity of staining with the NADH-TR technique. The Type 2c fibres, which possess both acid-stable and alkali-stable myofibrillar ATPase, are considered to represent intermediate fibres in the process of transformation from Type 2 to Type 1, rather than fibres with a dual innervation as has been suggested in the past. The implications of these histochemical findings are considered in relationship to the physiology of individual motor units and to the function of the extraocular muscles.
采用肌原纤维ATP酶和NADH - 四氮唑还原酶（NADH - TR）技术，研究了大鼠上直肌和内直肌（SR和MR）、上斜肌（SO）以及提上睑肌（LPS）的组织化学纤维类型组成。在SR、MR和SO中，可以识别出一个包含小纤维的外周区和一个包含小纤维与大纤维的中央区。这些肌肉的中央区存在四种纤维类型，分别归类为1型、2a型、2a'型和2b型。在外周区也识别出四种纤维类型——1型、2a型、2a'型和2c型。在LPS中，1型、2型、2a'型、2b型和2c型纤维均匀混合，无区域排列。1型、2a型、2b型和2c型纤维与大鼠肢体肌肉中公认的纤维类型相对应。2a'型和2a''型纤维是根据大小、模式以及NADH - TR技术染色的强度与2a型纤维区分开来的。2c型纤维同时具有酸稳定和碱稳定的肌原纤维ATP酶，被认为代表了从2型向1型转变过程中的中间纤维，而非如过去所认为的具有双重神经支配的纤维。本文结合个体运动单位的生理学以及眼外肌的功能，对这些组织化学研究结果的意义进行了探讨。
