Myosin heavy chain composition of the human sternocleidomastoid muscle

0386556 - FGÚ 2013 RIV DE eng J - Journal Article
Cvetko, E. - Karen, Petr - Eržen, I.
Myosin heavy chain composition of the human sternocleidomastoid muscle.
Annals of Anatomy-Anatomischer Anzeiger. Roč. 194, č. 5 (2012), s. 467-472. ISSN 0940-9602. E-ISSN 1618-0402
R&D Projects: GA MŠMT(CZ) MEB090910; GA MŠMT(CZ) LC06063
Institutional research plan: CEZ:AV0Z50110509
Keywords : immunohistochemistry * MyHC isoforms * muscle fibre types * sternocleidomastoid muscle
Subject RIV: FH - Neurology
Impact factor: 1.960, year: 2012

The sternocleidomastoid (SCM) muscle is one of the neck muscles responsible for head posture and control of head movement. It functions in rotation, inclination, rotraction, extension and flexion of the head, whilst chewing and in exerting ncreased respiratory efforts. This study is the first one describing the myosin heavy chain (MyHC) isoform composition of the SCM muscle of presumably healthy young males for the purpose of better understanding the contractile properties of the muscle as well as to help in evaluation of pathologically altered structure of the muscle. Autopsy samples were processed immunohistochemically to reveal the MyHC isoform composition. The muscle fibres expressed MyHC-1 (31.5%), -2a (29.7%) and -2x (4.3%) or co-expressed MyHC-2a with MyHC-2x (26.8%), MyHC-1 with MyHC-2a (4.1%) and/or MyHC-1, -2a with -2x (1.1%). In addition to the MyHC isoforms, characteristic of adult limb muscles, a very low percentage of muscle fibres (0.2–2.7%) expressed MyHC-neo, which is normally not found in adult limb muscles. Only two samples exhibited MyHC-neo at a rather higher percentage (6.3% and 7.5%) of muscle fibres. The high share of hybrid fibres and the presence of MyHC-neo in the SCM muscle differ from that of adult limb muscles where hybrid fibres are rare and the expression of immature MyHC isoforms occurs only in pathological or experimental conditions. Since the SCM muscle shares the same embryogenic potential as limb muscles, its distinct MyHC expression appears to be associated with twin innervation and with the intrinsic specialisation to perform multiple functions
Permanent Link: http://hdl.handle.net/11104/0219123