title: Influence of age on fibre type characteristics in the middle gluteal muscle of Andalusian foals.
abstract: 34 Andalusian foals of both sexes were divided into three age-groups (A = mean age 1 month, B = 7 months, C = 14 months). Samples of the right m. gluteus medius were stained for m-ATPase and NADH-TR in order to determine fibre type composition and size as well as the relative area occupied by each type. Results revealed no statistically significant variation in the proportion of type I fibre among the three age-groups. Significant differences were recorded, however, for type II fibres; an increase in the proportion of IIA fibres was accompanied by a decrease in IIB ones, the difference being most marked between groups A and B. IIB high-oxidative fibres also decreased, while IIB low-oxidative ones showed no significant variation. All fibre types increased significantly in size; types I and IIA recorded a threefold increase, whereas type IIB showed least growth. The relative area occupied by each type increased significantly between groups A and B, but only IIA fibres recorded a significant increase in relative area between groups B and C.
authors.affiliation: Department of Comparative Anatomy and Pathological Anatomy, Faculty of Veterinary Sciences, University of Córdoba, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Martínez-Galisteo
authors.forename: A
authors.initials: A
authors.lastname: Diz
authors.forename: E
authors.initials: E
authors.lastname: Agüera
authors.forename: J
authors.initials: J
authors.lastname: Vivo
mesh_terms: D000375:Aging; D000818:Animals; D002081:Buttocks / Q000033:anatomy & histology; D005260:Female; D006736:Horses / Q000033:anatomy & histology; D008297:Male; D009132:Muscles / Q000166:cytology* / Q000201:enzymology; D009218:Myosins / Q000032:analysis; D009246:NADH Tetrazolium Reductase / Q000032:analysis
chemical_list: D009246:NADH Tetrazolium Reductase; D009218:Myosins