Muscle fiber type-specific myofibrillar Ca(2+) ATPase activity after spinal cord injury.
Biopsies of the vastus lateralis muscle were analyzed to determine if increased energy demand of contraction, as indirectly reflected by myofibrillar Ca(2+) adenosine triphosphate activity (qATPase), contributes to greater fatigue in affected muscle of spinal cord injured (SCI) patients. The qATPase activity showed a fiber-type effect, IIax + IIx > IIa > I. Average fiber qATPase and fiber specific qATPase activities were not different between SCI and able-bodied controls, nor did they change over time. We suggest greater fatigue in SCI subjects early after injury does not reflect increased energy demand of contraction.
Castro
M J
MJ
Department of Exercise Science, The University of Georgia, 115F Ramsey Student Center, 300 River Road, Athens, Georgia 30602, USA.
Apple
D F
DF
Melton-Rogers
S
S
Dudley
G A
GA
D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology; D006801:Humans; D018485:Muscle Fibers, Skeletal / Q000201:enzymology* / Q000473:pathology; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000473:pathology; D009210:Myofibrils / Q000201:enzymology* / Q000473:pathology; D013119:Spinal Cord Injuries / Q000201:enzymology* / Q000473:pathology
D000252:Calcium-Transporting ATPases