OANA M. DUICU, DANINA MUNTEAN, O. FIRĂ-MLADINESCU, ANDREEA RĂDUCAN, SILVIA N. MIRICĂ, CORINA ŞERBAN, GERMAINE SĂVOIU, M. HÂNCU, A. CRISTESCU
Department of Pathophysiology, “Victor Babeş” University of Medicine and Pharmaceutics, Timişoara
The transversal deformation response force is a useful parameter for in vivo evaluation of skeletal muscle contractile response in basal conditions, electrical stimulation (induced tetany) or after myorelaxing drugs administration. The present device allows the recording of the transversal deformation response force which represents the parameter for the evaluation of skeletal muscle tone. The purpose of this study was to develop an experimental device suitable to evaluate the in vivo relaxing effects of a new purified Helleborus purpurascens root extract (ACSw05) on skeletal muscle tone. In this study we used Sprague Dawley rats (200–250 g), that were immobilized on the contention table, after they have been anesthetized with Nembutal 20 mg/kg i.p. Tetany was induced by supramaximal (120%) electrical stimulation. The evaluation of ACSw05 extract effects on skeletal muscle tone was performed by analyzing the plotted length-force curves; the follow-up period was 90 minutes. First we performed a control recording curve and afterwards we injected intramuscular 200 µl ACSw05 extract. We noticed a decrease of length-force curve slope and a 40% decrease of the contractile muscle response compared with the control recording curve. The relaxation curve slope hasn’t shown significant changes compared to the control recording curve. The device and method for skeletal muscle tone evaluation by measuring the transversal deformation response force can be used to compare the effects of different physical, chemical factors and drugs on skeletal muscle.
Key words: skeletal muscle, muscle tone, contractile response, myorelaxing drugs.