Changes in ureteral peristaltic activity induced by various stimuli

Abstract

AbstractThe interaction between the urinary bladder, the kidneys, and ureters is an area of interest to many investigators. Several investigators have suggested the existence of a feedback control system which would regulate urine production by the kidney and urine transport by the upper tract system. In certain conditions, such as urinary bladder outlet obstruction, this system would adjust the production and flow of urine as the situation dictates. The present study was designed to investigate the effects of changes in detrusor pressure, electrical stimulation of the pelvic nerves and the hypogastric nerves, and drugs on ureteral peristaltic activity and on renal nerve electricial activity. Cats anesthetized with alpha chloralose were monitored for changes in ureteral peristaltic frequency or spontaneous firing in renal nerves during changes in detrusor pressure, pelvic and hypogastric nerve stimulation, or drug administration.Increases in detrusor pressure decreased ureteral activity, while pelvic nerve and hypogastric nerve stimulation had little effect on renal nerve firing or ureteral peristaltic activity. Attempts were made to elicit changes in ureteral activity by the administration of acetylcholine, adenosine, adenosine nucleotides, and substance P. Acetylcholine increased and the purines decreased ureteral peristaltic frequency. Atropine and theopylline were used to antagonize the effects of drugs on ureteral peristaltic frequency. Theophylline antagonized only the adenosine responses.This study indicates that there is some interaction between the organs of the cat urinary tract. The results suggest the existence of a vesicoureteral reflex. However, the actual neural pathway for this reflex is still unproven. In addition, the evidence indicates the involvement of purines as neurotransmitters or neuromodulators in this reflex.