AOAA (2 mM) caused a transient (10 min) increase in motility.
HA (10 µM) caused a 'nitric oxide-like effect', smooth muscle hyperpolarization and relaxation, which were antagonized by 1H- [1,2,4] oxadiazolo [4,3-α] quinoxalin-1-one (ODQ , 10 µM).