IMMUNOCHEMICAL AND PROTEINOLOGICAL STUDY IN THE HEREDITARY MYOPATHY OF THE DIAPHRAGMATIC MUSCLES IN CATTLE

在几例因各种疾病而进行尸检的牛中，在横隔肌、肋间肌和心肌中发现了许多不伴有肌肉变性的核心样结构。在研究的213个8个月至15岁的头部中，有49例患有这种疾病。除了这些表现典型的遗传性膈肌肌病的核心样结构外，这49例病例还来自于该肌病的同一家系。为了探讨这种肌病的发病机制，分别制备了病变肌肉组织和正常肌肉组织的抗体进行免疫印迹分析。病变肌肉匀浆的免疫印迹显示有两条特异性条带(约55 kDa和65 kDa)，免疫反应性降低(约85 kDa)。虽然这项研究未能对这些异常蛋白进行鉴定，但它们似乎在这种肌病的发病机制中发挥了一定的作用。自20世纪90年代末以来，我们遇到了相当数量的扩张型心肌病病例。心肌组织学检查显示心肌纤维肥大、空泡化，纤维化严重。家系分析表明，该病牛为常染色体隐性遗传。这种心肌病的家系与荷斯坦-弗里西亚牛的遗传性隔肌肌病有重叠，尽管这些疾病表现出不同的病理。遗传基础可能支持来自同一家系树的那些不同的表型。

In several cases of the cattle which were submitted to the necropsy due to the various diseases, numerous core-like structures without accompanying muscle degeneration have been found in the diaphragmatic and intercostal muscles, and myocardium. Of the 213 heads studied from 8 months to 15 years old, 49 cases were affected this disorder. Addition to these pathological findings which showed a typical the core-like structures seen in the hereditary myopathy of the diaphragmatic muscles, the 49 cases were deribed from the same family line in the cases of this myopathy. These observations suggested that the 49 cases might have the potency of this myopathy.In order to investigate the pathogenesis of this myopathy, antibodies for the both diseased and normal muscle tissue, respectively, were prepared for the immunoblotting analysis. The immunoblots of homogenates of the diseased muscles demonstrated the presence of two specific bands (approximately 55 and 65 kDa) and decreased level of immunoreactivity (about 85 kDa). Although this study failed to reach the identification of these abnormal proteins, they seemed to play some part in the pathogenesis of this myopathy.Since the late 1990s, we encountered a considerable number of cases of the dilated cardiomyopathy. By histology, the myocardium revealed hypertrophy and vacuolation of the cardiac muscle fibers and severe fibrosis. Pedigree analysis of affected cattle indicated an autosomal recessive mode of inheritance. The family line of this cardiomyopathy overlapped with the one of the hereditary myopathy of the diaphragmatic muscles in Holstein-Friesian cattle, although those disorders exhibit a varying pathology. The genetic basis may support those different phenotypes appearing from one family tree.