Effects of cholinergic drugs on ureteral function in anesthetized dogs.

Abstract

We evaluated the effects of the nonselective muscarinic receptor agonist carbachol (CCh) and its antagonist atropine on ureteral function in anesthetized dogs. 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. 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. 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.