Summary.Mitochondrial osmiophilic bodies were found in the goblet cells of the small intestine in a group of muscular dystrophic mice. They were not found in any littermate normal control mice.The dense bodies were uniformly round in shape but dense content. Mitochondria with such dense bodies were distributed throughout the goblet cells. Adjacent absorbing epithelial cells had none of such mitochondrial bodies. Though the site of formation of the mitochondrial bodies remains to be investigated, the Golgi complex did not appear to be involved in the transportation of the dense bodies. Digestion of sections with ether-chlorofolm(1:1) slightly decreased the density of the mitochondrial body. Ruthenium red staining was not visible over the dense bodies but trace of Ru was detected by X-ray microanalysis.X-ray microanalysis indicated very few, if any, amounts of P and Ca, and it was not probable that phospholipid and calcium binding protein were the main constitution of these dense bodies.Comparative studies of dystrophic muscle of humans and experimental animals suggested that some alteration in the level of lipid metabolism was involved in muscular dystrophy.In search for morphological evidence of a different level of lipid metabolism in dystrophic mice (MAKITA, KIWAKI and SANDBORN, 1973), the epithelial cells of the small intestine were surveyed in comparatively long lived and severely affected dystrophic mice. In the ileum of four out of seven mice, one or two round dense bodies were found in many mitochondria of goblet cells. Since such dense bodies were not found in the littermate normal control animals they drew our attention, though we could not find similar dense bodies in a parallel study of muscular dystrophic hamster, and subjected the dense bodies to cytochemical and X-ray microanalysis.These dense bodies might be an indication of abnormality in the transportation of lipid-rich substance.Furthermore they might be potential evidence for a relationship between the morphology of mitochondria and the transport of dense substance in goblet cells under specific conditions.
Materials and MethodsSeven dystrophic mice of strain C57BL/6J-dydy and four normal controls were sacrificed at 177 days of age. Average body weights of the dystrophic and control mice were 12g and 26g, respectively.Under ether anaesthesia the animals were opened both in the thoracic and abdominal cavities and perfused with Ringer solution through the left cardiac ventricle, followed by injection of fixative consisting of 4%