[Effect of specialized contacts on fiber interaction during the spread of excitation in smooth muscle and myocardial tissues].

A mathematical model of closely packed parallel muscle fibres with side by side junctions was studied. High coupling coefficient for both heart and smooth muscle fibres was shown to be available at rather low junction permeability. The coupling coefficient for heart fibers is equal to 0.5 at specific junction membrane resistance as high as 100 omega cm2. For the same coupling ratio in smooth muscle the specific junction membrane resistance should be even greater (1000 omega cm2). The role of nexuses and tight junctions in conduction of excitation is discussed.