Tetanic depression in fast motor units of the cat gastrocnemius muscle

• Autorzy: Celichowski J. , Krutki P. , Lochynski D. , Grottel K. , Mrowczynski W.
• Języki publikacji: EN

Abstrakty

EN

Ability of muscle fibers to generate force is decreased when higher frequency of stimulation of motor units immediately follows lower frequency. This phenomenon called tetanic depression was found in rat medial gastrocnemius. However, it was not clear whether tetanic depression occurred only in rat muscle or it concerns all mammals. This study was conducted on motor units of cat medial gastrocnemius. Analyses were made at three successive trains of stimulation: 30 Hz, 20 and 30 Hz and again 30 Hz (the first pattern) or 40 Hz, 25 and 40 Hz and 40 Hz (the second pattern). In all fast units force generated within the middle tetanus was lower than force generated at the same, but constant frequency of stimulation applied earlier or later. The mean tetanic depression in 30 Hz tetani amounted to 10.9% for fast fatigable (FF) and 15.9% for fast resistant (FR) motor units, whereas in 40 Hz tetani mean values were 5.6% and 7.3% for FF and FR motor units, respectively. In slow motor units tetanic depression was not observed. These results proved the existence of tetanic depression in the feline muscle and indicated that its intensity depends on the fusion of tetanus. It has been concluded, that the tetanic depression is a general property of fast motor units in mammals.

Słowa kluczowe

EN

motor unit; muscle fibre; cat; gastrocnemius muscle; stimulation frequency; contractile force; skeletal muscle; tetanic depression

• Wydawca: -
• Czasopismo: Journal of Physiology and Pharmacology
• Rocznik: 2004
• Tom: 55
• Numer: 2
• Opis fizyczny: p.291-303,fig.,ref.

Twórcy

autor

Celichowski J.

• University School of Physical Education, Grunwaldzka 55, 60-352 Poznan, Poland

autor

Krutki P.

autor

Lochynski D.

autor

Grottel K.

autor

Mrowczynski W.