Procaterol is an agonist of β2-adrenergic receptors (β2-ARs). It binds to (Kd = 46 pM), and is selective for, β2-ARs over β1-ARs (Kd = 4,000 pM). Procaterol binds more potently to β2-ARs in isolated guinea pig lung than to β1-ARs in isolated guinea pig cardiac ventricle in the presence (IC50s = 175 and 1,660 nM, respectively) and absence of GTP (; IC50s = 55.1 and 1,660 nM, respectively). It inhibits contractions induced by acetylcholine in isolated guinea pig trachea (EC50 = 10.5 nM). In vivo, procaterol inhibits histamine-induced airflow obstruction in a guinea pig model of ovalbumin-sensitized asthma when administered via inhalation at a dose of 10 μg/ml.
