The effects of glucocorticoids on red and white muscles in the rat.
The effects of glucocorticoids on red and white muscles in the rat.
复制标题
糖皮质激素对大鼠红肌和白肌的影响。
作者：
L. Tice;A. Engel
肌无力与糖皮质激素过量的关联在临床上经常被观察到。“然而，给予此类类固醇并表现出虚弱的患者的活检标本的光镜研究并不总是显示出可以解释所观察到的虚弱的病理变化。在电子显微镜下，在类固醇肌病病例中观察到各种线粒体改变。这些包括异常大的线粒体、线粒体聚集体、线粒体空泡化、线粒体消失区域以及肌丝丢失区域。然而，没有一致的超微结构变化模式被确定，并且病变的演变仍然不清楚。在实验研究中，Ellis8报告了大剂量可的松给药后兔子广泛的肌肉坏死。Smith，9用组织化学方法报道了曲安奈德给药引起的兔肌肉肌病主要累及白色肌纤维。相比之下，D' agostino和Chiga'0在一项结合了光镜和电子显微镜的研究中报告说，可的松对兔子横膈膜中的红色纤维的影响最为显著。本研究提出的问题是，糖皮质激素是否能在大鼠肌肉中产生细微的结构变化，如果是这样，这些变化是否与人类类固醇肌病中观察到的变化有关。选取红色肌肉比目鱼肌和白色肌肉腓肠肌内侧头进行研究。这些肌肉分别含有相对均匀的红色和白色纤维，它们的线粒体含量的变化可能更容易评估。此外，由于对这些肌肉的不同功能需求及其不同的精细结构，观察它们是否会对致病刺激做出不同的反应是很有趣的。
The association of muscle weakness with glucocorticoid excess has often been observed clinically."A Light microscopic study of biopsy specimens from patients given such steroids and exhibiting weakness, however, has not always revealed pathologic change which could account for the weakness observed.' 3'5 With the electron microscope, a variety of mitochondrial alterations have been observed in cases of steroid myopathy.6 7 These have included unusually large mitochondria, mitochondrial aggregates, mitochondrial vacuolation, regions of mitochondrial disappearance, as well as areas of myofilament loss. No consistent pattern of ultrastructural change has been identified, however, and the evolution of the lesions has remained obscure. In experimental studies, Ellis8 reported widespread muscle necrosis in the rabbit after administration of large doses of cortisone. Smith,9 using histochemical methods, reported predominant involvement of white muscle fibers in myopathies induced in rabbit muscle by triamcinolone administration. In contrast, in a combined light and electron microscopic study, D'Agostino and Chiga'0 reported that red fibers in the rabbit diaphragm were most strikingly affected by cortisone administration. The questions asked in this study were whether fine structural changes could be produced in rat muscle by the administration of glucocorticoid hormones, and, if so, whether these changes could be related to those observed in human steroid myopathy. The soleus, a red muscle, and the medial head of the gastrocnemius, a white muscle, were selected for study. These muscles contain relatively homogeneous populations of red and white fibers respectively, and changes in their mitochondrial content may be more easily evaluated. In addition, because of the different functional demands on these muscles and their different fine structure, it was of interest to see if they would respond differently to pathogenic stimuli.