Skeletal muscle fibre-type shifting and metabolic profile in patients with chronic obstructive pulmonary disease.
The aim of this study was to examine the nature of fibre-type redistribution in relation to fibre metabolic profile in the vastus lateralis in chronic obstructive pulmonary disease (COPD) and COPD subtypes. Fifteen COPD patients (eight with emphysema stratified by high-resolution computed tomography) and 15 healthy control subjects were studied. A combination of myofibrillar adenosine triphosphatase staining and immunohistochemistry was used to identify pure, as well as hybrid fibre types. For oxidative capacity, fibres were stained for cytochrome c oxidase and succinate dehydrogenase activities, and glycogen phosphorylase for glycolytic capacity. The proportion of type-I fibres in COPD patients was markedly lower (16% versus 42%), especially in emphysema, and the proportion of hybrid fibres was higher (29% versus 16%) compared to controls. The proportion of fibres staining positive for oxidative enzymes was lower in COPD patients, which correlated with the proportion of type-I fibres. In COPD oxidative capacity was lower within IIA fibres. The authors conclude that fibre-type transitions are involved in the fibre-type redistribution in chronic obstructive pulmonary disease. Low oxidative capacity is closely related to the proportion of type-I fibres, but an additional reduction of oxidative enzyme activity is present within IIA fibres. Fibre-type abnormalities may be aggravated in emphysema.
Gosker
H R
HR
Dept of Pulmonology, University of Maastricht, The Netherlands. H.Gosker@pul.unimaas.nl
van Mameren
H
H
van Dijk
P J
PJ
Engelen
M P K J
MP
van der Vusse
G J
GJ
Wouters
E F M
EF
Schols
A M W J
AM
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000368:Aged; D003576:Electron Transport Complex IV / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000201:enzymology / Q000648:ultrastructure; D009210:Myofibrils / Q000201:enzymology; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism / Q000473:pathology*; D012129:Respiratory Function Tests; D013385:Succinate Dehydrogenase / Q000378:metabolism
D013385:Succinate Dehydrogenase; D003576:Electron Transport Complex IV; D000251:Adenosine Triphosphatases