The motor unit contractile properties of rat medial gastrocnemius muscle subjected to three months compensatory overload

• Autorzy: Krysciak K. , Drzymala-Celichowska H. , Krutki P. , Celichowski J.
• Języki publikacji: EN

Abstrakty

EN

Compensatory overload of medial gastrocnemius muscle was induced by bilateral tenotomy of synergists (lateral gastrocnemius, plantaris and soleus). Operated muscles were regularly voluntarily activated as after surgery rats were kept in wheel-equipped cages and additionally were exercised on a treadmill. 3 months after the surgery the final electrophysiological experiments were carried out. 106 motor units (MUs) of the overloaded muscle (OMG) and 154 MUs of the untreated muscle (MG) were studied. Results showed that OMG mass and its relation to the body mass were higher in comparison to MG. In OMG higher percentage of slow (S) and fast fatigable (FF) MUs and lower contribution of fast resistant (FR) MUs as compared to MG were noted. Changes in MUs contractile properties of OMG included: lower twitch force and higher tetanus force (resulted in lower values of the twitch-to-tetanus ratio), higher post-tetanic potentiation in all MUs types and shorter halfrelaxation time for S MUs. Changes in fatigue resistance concerned FF and S MUs: in OMG the fatigue index for FF was lower, but for S higher as compared to MG. In conclusion, the 3-month period of the muscle overload induced changes in MUs contractile properties accompanied by transformational processes.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2013
• Tom: 73
• Numer: Suppl.1
• Opis fizyczny: p.33

Twórcy

autor

Krysciak K.

• Department of Neurobiology, University School of Physical Education, Poznan, Poland

autor

Drzymala-Celichowska H.

• Department of Neurobiology, University School of Physical Education, Poznan, Poland

autor

Krutki P.

• Department of Neurobiology, University School of Physical Education, Poznan, Poland

autor

Celichowski J.

• Department of Neurobiology, University School of Physical Education, Poznan, Poland