Effects of cholinergic drugs on ureteral function in anesthetized dogs.

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.