Ureteral urine transport: changes in bolus volume, peristaltic frequency, intraluminal pressure and volume of flow resulting from autonomic drugs.

An experimental model which permits independent changes in ureteral peristalic frequency and bolus volume was employed to explore the effects of autonomic agonists on ureteral bolus volume, peristaltic frequency, intraluminal pressure and flow volume in the dog. Norepinephrine caused an increase in ureteral peristaltic frequency, an elevation in intraureteral baseline and contractile pressure and a decrease in bolus volume, with a resultant decrease in the rate of fluid transport. Isoproterenol caused a decrease in ureteral peristaltic frequency, and a fall in intraureteral baseline and contractile pressure, or it completely abolished peristalsis and bolus formation. These changes were accompanied by an increase in the rate of fluid transport. Acetylcholine caused an increase in ureteral peristaltic frequency, an elevation of intraureteral baseline pressure but no change in contractile pressure, and a small decrease in bolus volume with a resultant small decrease in the rate of fluid transport. These data suggest that the autonomic nervous system may affect urine transport through the ureter by not only regulating peristaltic frequency but also by influencing bolus volume.