• horse;
  • fibre typing;
  • immunoenzymatic method


Equine type I muscle fibres were characterised in 14 muscles by enzyme-linked immunosorbent assay (ELISA) with a monoclonal antibody specific for slow myosin heavy chains (MHC I). Slices of vastus lateralis, rectus femoris, biceps femoris, semitendinosus, semimembranosus, gluteus medius, gluteus superficialis, cutaneus trunci, masseter, triceps brachii, biceps brachii, deüoideus and diaphragm were obtained from a one-year-old Standardbred. For each muscle, 4 samples per slices were excised at different sites and 2 contiguous sub-samples were immediately frozen in liquid nitrogen and stored at –80 °C until analysed. Muscle proteins were specifically extracted and analysed by ELISA. The MHC I content varied widely in the different muscles from cutaneus trunci (9%) to masseter (69%). A 3-way analysis of variance showed that the MHC I content was different between muscles (P < 0.001) and within the sites studied (P < 0.01). The 2 contiguous sub-samples were not different from each other (P > 0.05). It is concluded that the ELISA method allowed the accurate measurement of a wide range of MHC I in equine muscles. This technique is less time consuming than histological techniques and offers new applications for muscle fibre typing.