Studies on the frog's sartorius at different stages of activity

The evolution of fatigue associated with isometric contraction in toad sartorius

“…Despite the fact that there is a considerable safety factor in the triggering of full tension development by the action potential (Falk, 1961), decreases in tension associated with marked reductions in the action potential have been reported for the case of prolonged single tetani (Seraydarian, Abbott & Williams, 1961). It is unlikely that we are facing that type of behaviour because in our case short tetani were used; probably there was no drop in the action potential and the evolution of the mechanical events was different.…”

Dissociation of Electrical and Mechanical Activity in the Frog's Sciatic-Sartorius Muscle Preparation Caused by Prolonged Immersion in Ringer Solution

“…It has been demonstrated that the failure of end-plate transmission occurs in both fatigued9)and denervated10,11)nerve-muscle preparations.Recently MER-TON(1954)5), SERAYDARIAN(1961) 6)and MASHIMA et al(1962)have shown that the E-C coupling processes diminished by muscular fatigue which was independent of the failure of end-plate transmission.Based on these reports,there may arise some questions ta investigate whether the E-C coupling processes are influenced by the prolonged immersion in Ringer solution and whether the immersion causes the same kind of effects as the denervation on the excitability and contractility of muscle. The present paper deals with the relationship between excitation and contraction in the isolated sciatic-sartorius preparation of frog immersed in Ringer solution for various periods up to 24 hours.…”