[Ultrastructure of the intercalary disks in cardiac muscle tissue of permanent and temporary residents at high altitudes].

In animals temporary adapted to the Alpine conditions, the intermembranous space of the intercalated disc is dilated 3-5 and more times, while in permanent inhabitants of the Alpine regions similar dilatation is not observed. Probably, in the latters numerous intercalated discs increase adhesive force of cardiomyocytes, extent of zones with low electrical resistance and increase contraction of myofibrills, thus promoting transmission of excitation from cell to cell.