germanium and Mitochondrial-Myopathies

The purpose of the study was to build up an animal model of mitochondrial myopathy in order to analyse the pathogenesis of the disease.. The skeletal muscles from Wistar rats treated with germanium dioxide for 24 weeks were analysed by histopathologic and electron-microscopic studies. A quantitative analysis was carried out in mitochondrial DNAs of these samples. The biological function of the model was determined.. An animal model of mitochondrial myopathy was built up, in which oxygen free radicals were increased and mitochondrial DNA copies were decreased contrasted with controls.. It suggested that environmental toxin may play a role in the pathogenesis of mitochondrial myopathy. The increase of oxygen free radicals is an important link causing the disease.

Topics: Animals; Disease Models, Animal; DNA, Mitochondrial; Germanium; Male; Mitochondria, Muscle; Mitochondrial Myopathies; Rats; Rats, Wistar; Reactive Oxygen Species

The purpose of this study were 1) to determine the earliest pathological changes of germanium dioxide (GeO2)-induced myopathy; 2) to determine the pathomechanism of GeO2-induced myopathy; and 3) to determine the minimal dose of GeO2 to induce myopathy in rats. One hundred and twenty five male and female Sprague-Dawley rats, each weighing about 150 gm, were divided into seven groups according to daily doses of GeO2. Within each group, histopathological studies were done at 4, 8, 16, and 24 weeks of GeO2 administration. Characteristic mitochondrial myopathy was induced in the groups treated daily with 10 mg/kg of GeO2 or more. In conclusion, the results were as follows: 1) The earliest pathological change on electron microscope was the abnormalities of mitochondrial shape, size and increased number of mitochondria; 2) The earliest pathological change on light microscope was the presence of ragged red fibers which showed enhanced subsarcolemmal succinate dehydrogenase and cytochrome c oxidase reactivity; 3) GeO2 seemed to affect the mitochondrial oxidative metabolism of muscle fibers; 4) GeO2 could induce mitochondrial myopathy with 10 mg/kg of GeO2 for 4 weeks or less duration in rats.

Topics: Animals; Electron Transport Complex IV; Female; Germanium; Histocytochemistry; Male; Mitochondrial Myopathies; Muscles; Rats; Rats, Sprague-Dawley; Succinate Dehydrogenase