mRNA Expression of Myosin Heavy Chain Isoforms in the Sphenomandibularis Portion of the Temporalis Muscle

The main objective of this study was to analyze by real-time quantitative polymerase chain reaction (RT-qPCR) the expression patterns myosin heavy (MHC) isoforms (MHC-I, MHC-IIa, MHC-IIx) in sphenomandibularis portion temporalis muscle. We expected find differences between and other portions that could be related functional characteristics identified electromyography. dissected right muscle ten adult human individuals (five men five women). Samples anterior posterior were obtained from each These samples analyzed RT-qPCR determine percentages MHC-I, MHC-IIa MHC-IIx isoforms. No significant However, there temporalis. Specifically, had a higher percentage MHC-I isoform (P=0.04) lower (P=0.003). pattern we observed reflects greater resistance fatigue, contraction speed, capacity force generation compared are consistent with electromyographic findings on these two portions.