Discrepancy between the renal pelvic fluctuations and the pacemaker discharges at the pelvi-calyceal border.

Experiments were performed in vitro to explore the influence of isoproterenol on the canine pelvi-ureteral system. The rhythmic changes of intrapelvic pressure became no longer manifest and simultaneously recorded electromyograms revealed disappearance of peristalsis at sites distal to the upper region of renal pelvis following application of isoproterenol, while the pacemaker at the pelvi-calyceal border continued to discharge with an enhanced pace. This result has demonstrated that the renal pelvic pressure recorded during treatment with isoproterenol did not reflect the pacemaker activity of the renal pelvis.