Mirabegron (YM178) is a potent, selective selective β3-adrenoceptor agonist with EC50 of 22.4 nM. Mirabegron (YM178) displays no activity against human beta1- and beta2-ARs. Mirabegron (YM178) exhibited relaxant effects of YM178 were evaluated in rats and humans bladder strips precontracted with carbachol (CCh. Mirabegron (YM178) (3 mg/kg, i.v.) decreased the frequency of rhythmic bladder contraction induced by intravesical filling with saline without suppressing its amplitude in anesthetized rats.
