Muscle fiber type-specific myofibrillar Ca(2+) ATPase activity after spinal cord injury.

M J Castro, D F Apple, S Melton-Rogers, G A Dudley

Journal: Muscle & nerve 2000;23(1):119-21

PMID: 10590416

Abstract

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.

Address: Department of Exercise Science, The University of Georgia, 115F Ramsey Student Center, 300 River Road, Athens, Georgia 30602, USA.

DOI: 10.1002/(sici)1097-4598(200001)23:1<119::aid-mus17>3.0.co;2-z