[Extracellular and intracellular electrogram of the heart at the site of suction electrodes in frogs].

On biological model of current due to damage with the suction electrode on the frog heart atrium in situ was given the survey of epicardial, intracellular and membraneous leads. The following data were found out: 1. Monophase epicardial recording is gradually starting from underpressure values -13.3 kPa to -40.0 kPa in the suction electrode when it is already constant; 2. In the course of sucking the originating monophase recording in lead with the suction electrode is spontaneously disappearing after a longer period (6-10 hrs) and changing into original multiphase one; 3. Intracellular potential up to 0.5 mm round suction electrode is lowered and it thus corresponds to monophase deformation in unipolar extracellular leads in this particular region; 4. After the original fall of the intracellular potential under the suction electrode higher underpressure causes the increase of this potential. Under local loss of membraneous tension the intracellular electrode reaches the branch of demarcation current inbetween the internal and external sides of sound membranes as well as the extracellular electrode.