A constant electrical activity of the renal pelvis correlated to ureteral peristalsis.

Using a bipolar macroelectrode, simultaneous recordings of both pelvic and ureteral electromyograms (EMG) were carried out in dogs. The recordings were performed at 3 stages of urine flow; oliguric, increasing and diuretic stages. The results showed that the interval of the pelvic discharge was constant while its speed of propagation was slower than that of the ureter (1.32 cm/sec and 2.12 cm/sec, respectively). At oliguric stage the interperstaltic interval in the ureter constituted a multiple of the pelvic discharge interval. Ureteral peristaltic rate reached that of the renal pelvis with increasing urine flow. These results are discussed in relation to a hypothesis of a renal pacemaker.