title: Age-dependent changes of enzyme activities in the different fibre types of rat extensor digitorum longus and gastrocnemius muscles.
abstract: The age-dependent change of metabolic profiles of SO (slow-oxidative), FOG (fast-oxidative glycolytic) and FG (fast-glycolytic) fibres of muscles digitorum longus and musculus gastrocnemius of rat from 14 days to 370 days was measured cytophotometrically. Fibres were classified visually and using cytophotometrical data from staining reactions for myofibrillar adenosinetriphosphatase (ATPase), succinate dehydrogenase (SDH) and alpha-glycerophosphate dehydrogenase (alpha-GPDH) in the same fibre. The fibre type population as percentage was estimated at different ages. The age-dependent change of enzyme activities was demonstrated in each fibre type. SDH-heterogeneity of FOG-fibres and consequently an overlap with SO-fibres was detected. The alpha-GPDH/SDH-activity quotient allowed to distinguish SO-, FOG- and FG-fibres, and the age-dependent change of activity quotient characterized the change of metabolic properties in the concerned fibre types. Whereas in gastrocnemius muscle the metabolic profile of FOG-fibres was similar to that of SO-fibres, in extensor digitorum longus muscle the metabolism of FOG-fibres was similar to that of FG-fibres. Between the two muscles differences were also shown for the fibre type responsible for changes of enzyme activities in the whole muscle, measured biochemically.
authors.affiliation: Institute of Anatomy, University of Leipzig, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Punkt
authors.forename: H
authors.initials: H
authors.lastname: Krug
authors.forename: J
authors.initials: J
authors.lastname: Huse
authors.forename: J
authors.initials: J
authors.lastname: Punkt
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000375:Aging / Q000378:metabolism; D000818:Animals; D015415:Biomarkers; D005260:Female; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D006651:Histocytochemistry; D008297:Male; D009132:Muscles / Q000166:cytology / Q000201:enzymology*; D010101:Oxygen Consumption / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013385:Succinate Dehydrogenase / Q000378:metabolism; D014059:Tongue / Q000166:cytology / Q000201:enzymology*
chemical_list: D015415:Biomarkers; D005954:Glucosephosphate Dehydrogenase; D013385:Succinate Dehydrogenase; D000251:Adenosine Triphosphatases