Enzyme-linked immunosorbent assay for myosin heavy chains in the horse

Abstract

― The content in slow and fast myosin heavy chains (MHC 1 and MHC 2) of 5 equine muscles was determined using an enzyme-linked immunosorbent assay. The results obtained with this immunoenzymatic method were compared with complementary techniques: electrophoresis and immunohistochemistry. Slices of masseter, diaphragm, tensor faciae latae, semitendinosus and cuta- neus trunci were obtained from a 12-year-old saddle horse after slaughter. Muscular proteins were specif- ically extracted to be analysed by ELISA. The technique used 2 complimentary monoclonal antibodies (MAb). MAb 1 was prepared from a human atrium specimen that reacted specifically against MHC 1. Mab 2 was prepared from myosin of rabbit psoas muscle and reacted against MHC 2. The masseter muscle contained solely MHC 1 (100%) and this was confirmed by electrophoresis and immunohis- tochemistry. By contrast, the cutaneus trunci was very poor in MHC 1 (1.3%) and was entirely composed of MHC 2 (98.7%) which was confirmed by the other techniques. The diaphragm, tensor fasciae latae and semitendinosus contained 89, 40 and 2% of MHC 1, respectively. It was concluded that this ELISA method made it possible to measure a wide range of MHC contents in equine muscles with a good reproducibility. The results were consistent with those of the other fibre typing techniques. More- over, this immunoenzymatic method is less time consuming than histological techniques and therefore offers new perspectives for muscle fibre typing in the horse. horse / muscle / myosin heavy chain / ELISA Rsum ― Mthode de dosage ELISA des chanes lourdes de la myosine chez le cheval. La com- position en chanes lourdes de la myosine lente (MHC 1) et rapide (MHC 2) a t dtermine dans 5 muscles quins par une mthode de dosage ELISA. Les rsultats obtenus par cette technique immu- noenzymatique ont t compars avec d'autres mthodes de typage des fibres musculaires : l'lec- trophorse et l'immunohistologie. Des tranches de masster, de diaphragme, de Tensor fasciae latae, de Semitendinosus, et de Cutaneus trunci ont t prleves sur un cheval de selle de 12 ans eutha- nasi pour colique. Les protines musculaires sont extraites par une mthode spcifique et les chanes lourdes de la myosine sont doses par une technique ELISA au moyen de 2 anticorps monoclonaux (MAb) complmentaires. MAb 1 a t prpar partir de muscle cardiaque de l'atrium humain et il ragit spcifiquement avec MHC 1. MAb 2 a t prpar partir de muscle psoas de lapin et ragit spcifiquement avec MHC 2. Le masster est exclusivement compos de MHC 1 (100%), ce qui est confirm par l'lectrophorse et l'immunohistologie. l'inverse, le Cutaneus trunci est presque exclusivement constitu de MHC 2 (98,7% MHC 2). Le diaphragme, le Tensor fasciae latae et le Semitendinosus contiennent respectivement 89, 40 et 2% de MHC 1. Cette technique de dosage ELISA des chanes lourdes de la myosine permet de mesurer avec une bonne reproductibilit des compositions trs variables en MHC sur les muscles du cheval. Les rsultats de dosage sont en accord avec les autres mthodes de dosage. De plus, pour effectuer le typage musculaire, la productivit de cette mthode immunoenzymatique est plus grande que les techniques histologiques, ce qui ouvre de nouvelles perspectives d'applications pour analyser des effectifs importants. cheval/muscle / chane lourde de la myosine / ELISA