EFFECTS OF CHOLINERGIC DRUGS ON URETERAL FUNCTION IN ANESTHETIZED DOGS

Abstract

PURPOSE: We evaluated the effects of the nonselective muscarinic receptor agonist carbachol (CCh) and its antagonist atropine on ureteral function in anesthetized dogs. MATERIALS AND METHODS: Drug effects were evaluated on elevated pressure in a completely obstructed ureter and peristalsis in its partially obstructed fellow ureters as well as on intravesical isovolumetric pressure. RESULTS: CCh (0.1 to 1.0 microg/kg intravenously) dose dependently decreased elevated pressure and peristalsis in completely and partially obstructed ureters, respectively, and increased intravesical isovolumetric pressure. On the other hand, atropine (0.1 to 1.0 mg/kg intravenously) had no significant effects on these 3 variables. Prior administration of atropine (1.0 mg/kg intravenously) completely inhibited the described CCh induced effects. CONCLUSIONS: Our results demonstrate that in anesthetized dogs cholinergic receptor stimulation has a suppressive effect on ureteral pressure and peristalsis in obstructed ureters, in contrast to its activation of bladder smooth muscle.