PACEMAKER POTENTIAL OF THE PELVI-URETERAL PERISTALSIS RECORDED BY INTRACELLULAR GLASS MICROELECTRODE

Abstract

It has already been confirmed by many experiments that the pelviureteral peristalsisis is controlled by the pacemaker and that the pacemaker exists at the pelvicalyceal border. In these experiments, EMG was recorded with extracellular surface electrodes. It was very difficult to record real action potential of the pacemaker and exclude artifacts. Applying the intracellular glass-microelectrode to the smooth muscle specimen obtained from the guinea-pig pelvicalyceal border, I succeeded in recording periodic spontaneous action potentials, so-called slow wave, which are characteristic of a pacemaker. By this experiment, it is proved that the pacemaker exists at pelvicalyceal border correctly and these new findings are confirmed.
(1) The part where slow wave is recorded in the pelvicalyceal border, especilly the part close to the papilla renalis. (2) Slow wave resembles that of cardiac SA node. It shows a biphasic pattern, and it is characteristic of a spontaneous excitable cell. (3) Resting phase potential in 42.3±1.1mV, spontaneous depolarizing potential is 12.1±0.7mV, and depolarizing period in 12/min. (4) Changing velocity of potential is 22.9±2.1mV/sec in the first slow depolarization phase, 50.9±9.5mV/sec in the following rapid depolarization phase, and 47.3±5.4mV/sec in the hyperpolarization phase.