MUSCLE-FIBER TYPE-SPECIFIC MYOFIBRILLAR ACTOMYOSIN CA(2-SCLEROSIS() ATPASE ACTIVITY IN MULTIPLE)

Biopsies of tibialis anterior muscle were analyzed to determine if inc reased energy demand of contraction, as indirectly reflected by myofib rillar actomyosin Ca2+ ATPase (qATPase) activity, contributes to sympt omatic fatigue in multiple sclerosis (MS). qATPase activity showed a f iber-type effect, IIax > IIa > I. Fiber-type qATPase activity, however , was not different between MS patients and healthy controls. We sugge st that fatigue in MS does not reflect increased energy demand of cont raction. (C) 1998 John Wiley & Sons, Inc.