Decreased osmotic stability of dystrophin-less muscle cells from the mdx mouse.
Human X-linked Duchenne and Becker muscular dystrophies are due to defects in dystrophin, the product of an exceptionally large gene. Although dystrophin has been characterized as a spectrin-like submembranous cytoskeletal protein, there is no experimental evidence for its function in the structural maintenance of muscle. Current hypotheses attribute necrosis of dystrophin-less fibres in situ to mechanical weakening of the outer membrane, to an excessive influx of Ca2+ ions, or to a combination of these two mechanism, possibly mediated by stretch-sensitive ion channels. Using hypo-osmotic shock to determine stress resistance and a mouse model (mdx) for the human disease, we show that functional dystrophin contributes to the stability of both cultured myotubes and isolated mature muscle fibres.
Menke
A
A
Developmental Biology Unit, University of Bielefeld, Germany.
Jockusch
H
H
D000818:Animals; D002470:Cell Survival; D016189:Dystrophin / Q000172:deficiency*; D005260:Female; D008297:Male; D051379:Mice; D009132:Muscles / Q000201:enzymology / Q000473:pathology*; D009336:Necrosis; D009997:Osmotic Pressure; D011770:Pyruvate Kinase / Q000378:metabolism
D016189:Dystrophin; D011770:Pyruvate Kinase