Abstract of article "Adaptive potential of human biceps femoris muscle demonstrated by histochemical, immunohistochemical and mechanomyographical methods"

DAHMANE, Raja, DJORDJEVIĆ, Srdjan, SMERDU, Vika. Adaptive potential of human biceps femoris muscle demonstrated by histochemical, immunohistochemical and mechanomyographical methods. Med. biol. eng. comput.. (Print ed.), Nov. 2006, vol. 44, iss. 11, str. 999-1006. (COBISS.SI-ID 2595179)

Abstract:

The goal of the study was to estimate the ability of biceps femoris muscle, a hamstring muscle crucial for biarticulate movement, to adapt to changed functional demands.
To achieve this a group of healthy sedentary men and 15 sprinters was measured by non-invasive mechanomyography (MMG) in order to monitor muscle twitch contraction times (Tc). Muscle twitch contraction times correlate with the proportions of slow and fast fibres in the muscle. Furthermore, the fiber type proportions in autoptic samples of BF in sedentary young men were determined according to histochemical reaction for myofibrillar adenosine triphosphatase (mATPase) to elucidate the data obtained by MMG method and to obtain reference data for the muscle. In one BF sample also myosin heavy chain (MyHC) isoform expression was demonstrated immunohistochemically. MMG measurements indirectly demonstrated that biceps femoris muscle has a strong potential to transform into faster contracting muscle after sprint training, since the average Tc in sprinters was much lower (19.5 ± 2.3 ms) than in the sedentary group (30.25 ± 3.5 ms). Histochemical and immunohistochemical analysis of BF muscle also also show a high adapting potential of this muscle. Beside type 1, 2a and 2• (2b) fibres a relatively high proportion of intermediate type 2c fibres (5.7% ± 0.7), which co-expressed MyHC-1 and -2a, was found. That is why type 2c might represent a potential pool of fibres, capable of transformation either to slow type 1 or to fast type 2a in order to tune the functional response of BF muscle according to the actual functional demands of the organism.