[Fiber interaction during impulse propagation in smooth muscle and myocardial tissues. Electrotonic interaction]

Electrotonic potential appearing in a single muscle fibre during excitation spread was calculated in the mathematical model of closely packed parallel fibres. Electrotonic depolarization values for heart and smooth muscle were shown to be 10--20 mV, that is comparable to the excitation threshold value. Tissue parameter values were estimated where the coupling coefficient was maximal. The parameter values proved to be similar to those measured in heart and smooth muscles. The data obtained indicate that the electrotonic interaction of muscle fibres should play a significant role in excitation conduction.