Effect of corticosteroids on respiratory muscle histopathology.
Effect of corticosteroids on respiratory muscle histopathology.
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皮质类固醇对呼吸肌组织病理学的影响。
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
R. Cherniack
中科院分区：
文献类型：
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作者：
G. Ferguson;C. Irvin;R. Cherniack
我们评估了皮质类固醇给药对家兔呼吸肌的病理改变，并将其与周围骨骼肌的病理改变进行了比较。在肌内注射可的松3周后，测定膈肌、肋间肌、胸锁乳突肌、指长伸肌和比目鱼肌的大体和显微病理以及组织化学变化。皮质类固醇在除比目鱼肌外的所有肌肉中引起明显的病理改变。虽然肉眼病理变化最大的是指长伸肌，显微镜下的变化最大的是膈肌。总肌纤维体积的减少在膈肌、胸锁乳突肌和指长伸肌中也类似。在使用皮质类固醇后，肌肉中肌肉纤维的种类和数量的组成并没有改变。除比目鱼肌外，其余肌肉均有明显的肌纤维萎缩。在横膈膜中，皮质类固醇诱导所有纤维类型的萎缩，包括I型纤维。外周骨骼肌和其他呼吸肌未见I型纤维萎缩。另一方面，皮质类固醇诱导肋间肌和胸锁乳突肌的IIb型肌纤维选择性萎缩，类似于外周骨骼肌。这些发现表明，皮质类固醇对横膈膜的作用是独特的，不能从皮质类固醇对周围骨骼肌的作用推断出它对横膈膜的作用。此外，这些病理变化可能与功能相关，因为I型纤维的萎缩可能导致肌肉耐力的降低。
Pathologic alterations induced by corticosteroid administration were evaluated in the respiratory muscles and compared to those in the peripheral skeletal muscles of the rabbit. Alterations in gross and microscopic pathology as well as histochemistry were determined in the diaphragm, intercostal, sternocleidomastoid, extensor digitorum longus, and soleus muscles following 3 wk of intramuscular cortisone injections. Corticosteroid administration induced significant pathologic changes in all the muscles except the soleus. Although gross pathologic changes were greatest in the extensor digitorum longus, microscopic changes were greatest in the diaphragm. Reductions in total muscle fiber volume were similar in the diaphragm, sternocleidomastoid, and extensor digitorum longus muscles. The composition of muscle fiber types and the number of fibers in a muscle were not altered in any of the muscles studied following corticosteroids. There was significant atrophy of individual muscle fibers in all the muscles except the soleus. In the diaphragm, corticosteroids induced atrophy of all fiber types, including type I fibers. Atrophy of type I fibers was not present in the peripheral skeletal muscles or the other respiratory muscles. On the other hand, corticosteroids induced selective atrophy of type IIb muscle fibers in the intercostal and sternocleidomastoid muscles similar to that in the peripheral skeletal muscles. These findings suggest that the effect of corticosteroids on the diaphragm is unique, and one cannot extrapolate form the effect of corticosteroids on peripheral skeletal muscles to that in the diaphragm. In addition, these pathologic changes may have functional relevance, since atrophy of type I fibers may result in a reduction in muscle endurance.