Decreased osmotic stability of dystrophin-less muscle cells from the mdx mouse
Article Abstract:
Two forms of muscular dystrophy (genetically determined conditions characterized by progressive muscle weakness and wasting) are Duchenne (inevitably fatal) and Becker muscular dystrophy, both of which are associated with the production of abnormal dystrophin. The dystrophin gene product in such cases is abnormally large. The function of this muscle protein is not known; to learn more about this issue, an animal model of dystrophy was investigated. Experiments were performed on muscle fibers from mice with different pedigrees with respect to the dystrophin gene. Muscle fibers from mice lacking dystrophin were more sensitive to sudden exposure to a hypo-osmotic bath (containing low concentrations of osmotically active substances), a reaction called osmotic shock, than fibers from control mice, dying within 12 minutes of exposure. This vulnerability was not seen in muscle fibers from mice with a different muscle disease (myotonia). Anatomical differences between dystrophic and control muscle fibers were also noted that indicated a history of extensive necrosis (cell death) and regeneration. Possible physiological events that could lead to cell death in the experimental system are discussed. It is possible that in Duchenne or Becker muscular dystrophy, relatively slight, but constant, reductions occur in the stability of the affected muscle fibers, leading to the abnormalities associated with the disorders. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1991
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Localization of dystrophin to postsynaptic regions of central nervous system cortical neurons
Article Abstract:
Patients with Duchenne muscular dystrophy (DMD) are missing the protein dystrophin, a protein present in muscles. Individuals with DMD also have moderate cognitive (thinking) impairment, but abnormalities in the brain have not been previously identified. Studies have shown that it is possible that dystrophin may be synthesized in low levels in the brain. These studies have been incomplete because available detection methods are not very sensitive. An antibody was developed that is very sensitive for detecting dystrophin. In mice, dystrophin was found to be present in the muscles of blood vessels in the brain, and also in the nerve cells in regions of the cerebellum and cerebrum of the brains of normal mice, but it was absent in mice that were lacking dystrophin due to genetic defects. The cerebrum is associated with cognitive function. This research suggests that alterations in dystrophin in the brain may be the cause of the cognitive impairment in DMD. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1990
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Dystrophin expression in the mdx mouse restored by stem cell transplantation
Article Abstract:
It has been established that bone marrow or muscle side population cells seem to provide a means for systemic, rather than local, muscle repair. This is the result of the delivery of the cells throughout the vascular system. It appears that the transplantation of different stem cell populations could offer a form of treatment for muscular dystrophy and other diseases in which the systemic delivery of therapeutic cells to sites throughout the body is vital. This research has also provided valuable new information about the biological properties of different stem cell populations.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1999
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