Changes in fibre type composition of gluteus medius and semitendinosus muscles of Dutch Warmblood foals and the effect of exercise during the first year postpartum

Abstract

Summary In order to obtain broader insights into the equine musculoskeletal system, we studied the fibre type composition of 2 locomotory muscles in biopsies from Dutch Warmblood foals taken at 3 different ages in the first year postpartum. The muscle fibre types were determined histochemically as well as immunohistochemically. ATPase‐characterised IIB fibres appear to express either IId or type IIa plus IId myosin heavy chain (MHC). A high percentage of fibres classified as IIA with ATPase expressed both fast types of MHC. The type I classification by the 2 methods matched almost completely. There was an increase with age of fibres expressing I and IIa MHC in the gluteus medius. At the same time, there was a decrease of fibres expressing IId MHC and fibres co‐expressing MHC IIa and IId. MHC expression of the semitendinosus muscle did not change over time at first, but from age 22–48 weeks there was a decrease in the percentage of type IId fibres. In general, the gluteus medius contained more type I fibres but fewer type IId fibres compared to the semitendinosus. At most ages the fibre type compositions of both muscles correlated with one another. To examine the effect of exercise, one‐third of the foals were given box rest, one‐third received training and one‐third kept at pasture during the first 22 weeks of life. The 3 exercise groups differed in their fibre type composition; however, these differences could not be attributed to the effect of exercise.

Muscle fibre type composition in young and racing Swedish cold-blooded trotters

“…Nowadays this method is often used since a more detailed picture of the muscle and its adaptations to different kinds of stimuli can be obtained [10][11][12][13] . Nowadays this method is often used since a more detailed picture of the muscle and its adaptations to different kinds of stimuli can be obtained [10][11][12][13] .…”

Biometry by ultrasonography of the epaxial and pelvic musculature in equines trained with Pessoa's rein

“…O LD é o músculo epaxial mais superfi cial, sendo a atrofi a muito visível, enquanto que o GM, por ter também função postural, encontra-se em áreas mais profundas (DINGBOOM et al, 2002). Ainda, STUBBS et al (2010) relacionaram atrofi a destas musculaturas, com a ocorrência de cavalos com lombalgia.…”

“…Músculos do membro pélvico, como o Biceps Femoris e Semitendinosus, foram escolhidos por sua importante função na locomoção, sendo considerados músculos propulsivos (DINGBOOM et al, 2002). Estes músculos são caracterizados por terem grandes volumes e especializados em produzir muita força para realização do movimento (PAYNE et al, 2005).…”

Myosin heavy chain pattern in the Akhal-Teke horses

“…It has been previously shown that muscle fibers with high oxidative potential have higher resistance and capacity for regeneration during and after exercise (Votion et al, 2007;Seene et al, 2008 and. Surveys have shown that age causes changes in muscle fiber types of MyHC isoform patterns and oxidative potential in horse skeletal muscle (Dingboom et al, 2002;Lehnhard et al, 2004). Horses older than 20 years had significantly less of type I and type IIA fibers in skeletal Leisson, Alev, Kaasik, Jaakma and Seene muscle and more of type IIx fibers than the young horses (Lehnhard et al, 2004;Kim et al, 2005).…”