Stretch-activated channels in stretch-induced muscle damage: role in muscular dystrophy.
1. Stretch-induced muscle injury results in the damage that causes reduced force and increased membrane permeability. This muscle damage is caused, in part, by ionic entry through stretch-activated channels and blocking these channels with Gd3+ or streptomycin reduces the force deficit associated with damage. 2. Dystrophin-deficient muscles are more susceptible to stretch-induced muscle injury and the recovery from injury can be incomplete. We have found that Na+ entry associated with stretch-induced injury is enhanced in dystrophin-deficient muscles and that blockers of stretch-activated channels are capable of preventing ionic entry and reducing muscle damage. 3. A model is presented that proposes links between stretch-induced injury, opening of stretch-activated channels, increased levels of intracellular ions and various forms of muscle damage. Although changes in Na+ accompany stretch-induced muscle injury, we believe that changes in Ca2+ probably have a more central role in the damage process.
Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Ella W
EW
Yeung
David G
DG
Allen
D000818:Animals; D016189:Dystrophin / Q000172:deficiency; D006801:Humans; D009470:Muscle Spindles / Q000187:drug effects / Q000502:physiology*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D009136:Muscular Dystrophies / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D009137:Muscular Dystrophy, Animal / Q000378:metabolism / Q000503:physiopathology; D026941:Sodium Channel Blockers / Q000494:pharmacology / Q000627:therapeutic use; D015222:Sodium Channels / Q000378:metabolism
D016189:Dystrophin; D026941:Sodium Channel Blockers; D015222:Sodium Channels