Skinned single fibers from normal and dystrophin-deficient dogs incur comparable stretch-induced force deficits.
Intact dystrophin-deficient canine muscles were previously shown to incur greater-than-normal stretch-induced force deficits. Here we tested the hypothesis that maximally activated detergent-treated (skinned) single fibers from normal and dystrophin-deficient dogs would incur comparable force deficits after stretch. Skinned cranial sartorius (CS) fibers from dystrophin-deficient and normal dogs were calcium-activated (pCa 4.5) and rapidly stretched. A single 30% stretch induced force deficits of 27.07 +/- 3.9% and 29.7 +/- 4.8% in dystrophin-deficient (n = 22) and normal (n = 18) fibers, respectively. Our data support the hypothesis that maximally activated skinned single fibers from normal and dystrophin-deficient dogs incur comparable force deficits after stretch. Our findings suggest that knowledge of the extent of stretch-induced force deficits following repeated stretch-activations in the GRMD dog may be useful to assess future therapeutic interventions aimed at replacing dystrophin in the sarcolemmal membrane.
Childers
Martin K
MK
Department of Physical Medicine and Rehabilitation, School of Medicine, University of Missouri-Columbia, DCO 46.00, One Hospital Drive, Columbia, Missouri 65212, USA. childersmk@health.missouri.edu
Staley
Jerry T
JT
Kornegay
Joe N
JN
McDonald
Kerry S
KS
D000818:Animals; D003902:Detergents; D004195:Disease Models, Animal; D004285:Dogs; D016189:Dystrophin / Q000172:deficiency*; D009119:Muscle Contraction / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000378:metabolism* / Q000473:pathology; D018908:Muscle Weakness / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D009137:Muscular Dystrophy, Animal / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D018995:Myosin Heavy Chains / Q000378:metabolism; D012508:Sarcolemma / Q000378:metabolism
D003902:Detergents; D016189:Dystrophin; D018995:Myosin Heavy Chains