Abstract
The present paper deals with the phenomenon induced by the application of guanidine to the striated muscle.
Guanidine enhances the excitablity of the terminal fibres, thus repetitive excitations are induced by a single nerve impulse. This impulse then is transmitted to the muscle fibres through the end-plates on one hand, and also ascends antidromically through the motor nerve on the other hand.
In the muscle treated with guanidine, even a direct stimulation induces repetitive excitation. In this case, however, the action current stimulates the terminal fibres, the excitability of which is enhanced by guanidine, to induce repetitive excitation in this portion, then this excitation is transmitted again to the muscle through the end-plate to induce muscular contraction. Simultaneously, the group of impulses antidry omically ascends through the nerve fibres.
Furthermore, when the action of guanidine progressed, repetitive excitation is induced also in the terminal fibre, without being stimulated, muscle contraction occurs, then, on the other hand, the group of impulses induced in the terminal fibre antidromically ascends through the nerve fibres.
As to the portion of the terminal fibre in which this antidromic impulse occurs, Toriumi, one of the present authors, has investigated the similar phenomenon by TEA and reported. Therefore, the present paper does not deal with this question. Presumably, the point on which guanidine acts is the same as that by TEA. Guanidine possesses the action to potentiate the end-plate potential.
