A constant electrical activity of the renal pelvis correlated to ureteral peristalsis
Tohoku journal of experimental medicine
TSUCHIDA, S. and YAMAGUCHI, O. A Constant Electrical Activity of the Renal Pelvis Correlated to Ureteral Peristalsis . Tohoku J. exp. Med., 1977, 121 (2), 133-141-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
... speed of propagation was slower than that of the ureter (1.32 cm/sec and 2.12 cm/sec, respectively). At oliguric stage the interperistaltic 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 pelvic pacemaker. pelvic electromyography; ureteral peristalsis; pacemaker In spite of numerous studies on upper urinary tract, a functional relationship between the renal pelvis and the ureter is not yet completely understood. To explain this relation, a hypothesis of pacemaker of ureteral peristalsis has been suggested by several workers (Bozler 1942; Shiratori and Kinoshita 1961; Kobayashi 1964; Weiss et al. 1967 ). However, a considerable confusion had surrounded this theory because it was generally difficult to prove a reliable measurement in vivo. Recently, Constantinou (1974) clearly showed that the frequency of pelvic pressure oscillation was constant for various urine flow rates, and ureteral peristaltic rate was directly related with an integral division of this basic pacemaker rate. More recently, Hrynczuk and Schwartz (1975) , by the use of a subtraction amplifier with a computer system, analyzed the rhythmic pressure changes of the pelvis concluding the same results. In this paper, we demonstrate the simultaneous recordings of the pelvic and ureteral EMG and examine a concept of renal pelvic pacemaker as being responsible for the initiation and conduction of ureteral peristalsis. MATERIALS AND METHODS Ten mongrel dogs weighing between 18 and 25 kg were used for the experiment. The dogs were anesthetized with an intravenous injection of sodium pentobarbital (Nembutal 25-30mg/kg). Saline (0.9%) was slowly infused throughout the experiment. The kidney, ureter and bladder were exposed by a midline incision.