NONINVASIVE ELECTROGASTROGRAPHY .1. CORRELATION BETWEEN THE GASTRIC ELECTRICAL-ACTIVITY IN DOGS WITH IMPLANTED AND CUTANEOUS ELECTRODES

Experiments were made on dogs with bipolar silver ball-shaped electrod es chronically implanted on the muscle wall of the stomach. The electr ical activity of the gastric muscle wall (electrogastromyogram-EGMG) w as characterized by slow potential changes during the quiescent period of the migrating myoelectric complex (MMC) and bursts of spike potent ials during the activity period of MMC. Cutaneous (surface) electrodes were placed on the abdominal wall. Waves with a rhythm of 4.5 - 5 cpm were led off by the cutaneous electrodes (electrogastrogram - EGG), s imultaneously with the EGMG. The bursts of spike potentials with the s low gastric potentials in the EGMG corresponded to an increase of the amplitude of the waves in the EGG. Good correlation was found between the number and frequency of spike potentials in a group and the wave a mplitude in the EGG. EGG recorded on an electrogastrograph designed by us was characterized by low-amplitude waves corresponding to the slow waves during the period of quiescence of MMC and high-amplitude waves corresponding to the bursts of spike potentials during the activity p eriod of MMC. Therefore it is possible to determine the MMC of the sto mach by the changes in the amplitude of the waves in the EGG.