The effect of arylazido aminopropionyl ATP on atropine resistant contractions of the cat urinary bladder

This work was designed to study neurogenic, atropine resistant contractions of the cat urinary bladder. Urinary bladder contractions were induced by pelvic nerve stimulation (PNS) and the administration of acetylcholine (Ach) and purine compounds. The results show that atropine (2 mg/kg) depresses the maintained portion (phase 2) of PNS-induced contractions and Ach-induced contractions while having no effect on the initial portion (phase 1) of the PNS-induced contractions or those contractions induced by the purines. Arylazido aminopropionyl ATP (ANAPP 3), an ATP antagonist, depressed phase 1 of the PNS contraction and the purine induced contractions. These results suggest that ATP is responsible for at least part of the atropine-resistant contractions of the cat urinary bladder.