Muscle fiber type-specific myofibrillar actomyosin Ca2+ ATPase activity in multiple sclerosis.
Biopsies of tibialis anterior muscle were analyzed to determine if increased energy demand of contraction, as indirectly reflected by myofibrillar actomyosin Ca2+ ATPase (qATPase) activity, contributes to symptomatic fatigue in multiple sclerosis (MS). qATPase activity showed a fiber-type effect, IIax > IIa > I. Fiber-type qATPase activity, however, was not different between MS patients and healthy controls. We suggest that fatigue in MS does not reflect increased energy demand of contraction.
Castro
M J
MJ
Department of Exercise Science, University of Georgia, Athens 30602, USA.
Kent-Braun
J A
JA
Ng
A V
AV
Miller
R G
RG
Dudley
G A
GA
D002118:Calcium / Q000378:metabolism*; D006801:Humans; D009103:Multiple Sclerosis / Q000201:enzymology* / Q000503:physiopathology; D009119:Muscle Contraction; D018656:Muscle Fibers, Fast-Twitch / Q000201:enzymology; D018485:Muscle Fibers, Skeletal / Q000201:enzymology*; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000503:physiopathology; D009218:Myosins / Q000378:metabolism*; D013194:Staining and Labeling
D009218:Myosins; D002118:Calcium