[Studies on the in vivo pacemaker potentials of the canine renal pelvis]

In vivo pacemaker potentials of canine renal pelvis were able to be recorded by our new method. Potentials recorded at the pelvicalyceal region of canine renal pelvis in vivo had two phasic slow rising wave form that had duration of 0.2 sec, amplitude of 20 microV and discharge interval of about 5 sec. Furthermore, the discharge interval of ureter EMGs was a integral multiple of that of pacemaker potentials. In diuretic state by intravenous administration of furosemide, pacemaker potentials showed no change in wave form and discharge interval. However, ureter EMGs occurred more frequently to correspond to pacemaker potentials one to one. Noradrenaline and isoproterenol had no action on pacemaker potentials. To the contrary, ureter EMGs were increased by noradrenaline and were decreased by isoproterenol. Acetylcholine had a great variety of action on both pacemaker potentials and ureter EMGs. These results suggest that the pelvicalyceal region as thought to be the pacemaker of ureteral peristalsis is controlled under the influence of parasympathetic nerve system and the ureter is controlled under the influence of both sympathetic and parasympathetic nerve systems.