Ractopamine (hydrochloride)

Ractopamine is a trace amine-associated receptor 1 (TAAR1) agonist.¹ It increases chloride conductance in X. laevis oocytes expressing the human cystic fibrosis transmembrane conductance regulator (CFTR) and mouse TAAR1 (EC₅₀ = 16 µM), an effect that can be blocked by the TAAR1 antagonist EPPTB (Item No. 34330). It selectively induces chloride conductance in TAAR1- and CFTR-expressing oocytes over those expressing the human β₂-adrenergic receptor (β₂-AR) and CFTR at 36 µM. However, it is also considered a β₂-AR agonist that binds to β₂-ARs (K_i = 0.18 µM for the recombinant human receptor expressed in Sf9 cells) and induces relaxation of isolated guinea pig trachea with an EC₅₀ value of 9.1 nM.² Formulations containing ractopamine have been used as food additives in livestock to increase weight gain and leanness and improve feed efficiency.

WARNING This product is not for human or veterinary use.

1. Liu, X., Grandy, D.K., and Janowsky, A. Ractopamine, a livestock feed additive, is a full agonist at trace amine-associated receptor 1. J. Pharmacol. Exp. Ther. 350(1), 124-129 (2014).

2. Kern, C., Meyer, T., Droux, S., et al. Synthesis and pharmacological characterization of β₂-adrenergic agonist enantiomers: Zilpaterol. J. Med. Chem. 52(6), 1773-1777 (2009).