tcsc0915 Mirabegron

Mirabegron is a selective β₃-adrenoceptor agonist with EC₅₀ of 22.4 nM.







IC50 & Target: EC50: 22.4 nM (β₃-adrenoceptor)^[1]

In Vitro: Mirabegron (YM178) increases cyclic AMP accumulation in Chinese hamster ovary (CHO) cells expressing human β₃-adrenoceptor (AR). EC₅₀ value is 22.4 nM. EC₅₀ values of Mirabegron for human β₁- and β₂-ARs are 10,000 nM or more, respectively. EC₅₀ of Mirabegron in rat bladder strips precontracted with 10^-6 M Carbachol (CCh) is 5.1 μM, whereas that in human bladder strips precontracted with 10^-7 M CCh is 0.78 μM. Mirabegron concentration-dependently increases the accumulation of cAMP in CHO cells expressing human β₃-ARs, with an EC₅₀ value and I.A. of 22.4 nM and 0.8, respectively. Mirabegron has little agonistic effect on β₁- and β₂-ARs. Compared by EC₅₀ value, Mirabegron is approximately one third as potent as isoproterenol. The maximal relaxant effects of Mirabegron are 94±1%, that of CCh, indicating that Mirabegron acts a full agonist in the rat bladder. The maximal relaxant effects of Mirabegron is 89.4±2.3%^[1].

In Vivo: Mirabegron (YM178) produces a dose-dependent decrease in the frequency of rhythmic bladder contraction in anesthetized rats. In contrast, Mirabegron does not decrease the amplitude of rhythmic bladder contraction at up to 3 mg/kg i.v.. On the contrary, Oxybutynin significantly increases the frequency of rhythmic bladder contraction and decreased its amplitude at doses of 0.272 mg/kg i.v. or more^[1].