Basic physiological studies of the effects of autonomic drugs on the pacemaker of renal pelvic peristalsis

An electromyographic study of the effects of noradrenaline, isoproterenol, and acetylcholine on the calyceopelviureteral system was performed in isolated canine pyeloureteral preparations with continuous infusion of oxygenated Krebs‐Ringer solution into the renal pelvis to provide a condition of constant urine volume. The calyceal pacemaker was slightly stimulated by noradrenaline and acetylcholine and was also quickened in pace by isoproterenol. Noradrenaline caused a marked elevation of renal pelvic pressure and enhancement of propagation of peristalsis generated at the pacemaker region with an increase in frequency of ureteral peristalsis. In contrast, isoproterenol lowered the renal pelvic pressure to an extent of pressure wave disappearance and concomitant blockade of peristaltic movement propagation to the ureter, with consequent suppression of ureteral peristalsis. Acetylcholine slightly reduced the renal pelvic pressure but at the same time exerted a marked effect on the ureter, causing a transient increase in frequency of ureteral peristalsis.