Distribution of different fibre types of M. extensor carpi radialis longus of the rat.
As revealed by the NADH-diaphorase and myosine ATPase, the M. extensor carpi radialis longus of the rat possesses at least 3 main kinds of fibres, with different distribution on the superficial and deep portions of the muscle. The superficial portion revealed that 67.68% are FG (fast-twitch-glycolytic) fibres, 14.72% are FOG (fast-twitch-oxidative) fibres and 17.60% are SO (slow-twitch-glycolytic) fibres. Already the deep portion revealed that 71.29% are SO (slow-twitch-glycolytic) fibres, 17.46% are FOG (fast-twitch-oxidative-glycolytic) fibres and 11.25% are FG (fast-twitch-glycolytic) fibres. The miosine ATPase reaction was used to demonstrate contracting characteristics. These findings suggest that the movements of fast contraction of the M. extensor carpi radialis longus are predominant.
Rodrigues
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Ade C
Department of Anatomy and Morphology, State University, Julio de Mesquita Filho, Botucatu, São Paulo, Brazil.
Silva M dal
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Pai
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D000251:Adenosine Triphosphatases / Q000032:analysis; D000818:Animals; D008058:Dihydrolipoamide Dehydrogenase / Q000032:analysis; D006651:Histocytochemistry; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000201:enzymology; D051381:Rats / Q000033:anatomy & histology*
D008058:Dihydrolipoamide Dehydrogenase; D000251:Adenosine Triphosphatases