Mdx respiratory impairment following fibrosis of the diaphragm

Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease that causes respiratory or cardiac failure and results in death at about 20 years of age. An animal model of DMD, the mdx mouse, is commonly used to estimate dystrophic pathology. The pathological features of limb muscles are relatively mild, however the diaphragm is severely affected and exhibits a degenerative pattern similar to that observed in human DMD. Although, the muscle strength assay of the dystrophic diaphragm has been used to estimate mdx respiratory impairment, systemic functional assessments compared with histopathological analysis have not been demonstrated. Here, we report a sensitive procedure using whole-body plethysmography to monitor respiratory parameters detected during early respiratory insufficiency in the mdx mouse. The dystrophic changes in the diaphragm lead to respiratory dysfunctions. These methods may be useful to assess the therapeutic approaches for the mdx mouse.