Description:

Ki: 1095 nM for A2A receptor

The adenosine A2A receptor is a G-protein-coupled receptor that has been extensively studied during the past few decades because it offers numerous possibilities for therapeutic applications. Regadenoson (CVT-3146) is a highly selective, potent, low affinity A2A adenosine agonist.

In vitro: Regadenoson was selective for the A2A adenosine receptor versus the A1, A2B, and A3 receptors in binding and functional studies. Regadenoson was also found to be a full and potent agonist to cause coronary vasodilation, a response that has a very large A2A receptor reserve [1].

In vivo: In a study of 10 conscious dogs, authors compared intravenously injected regadenoson to that of adenosine. Regadenoson caused a dose-dependent increase of coronary blood flow (CBF), whereas adenosine was less potent but produced equivalent hyperemia. Thus, authors concluded that regadenoson is a potent coronary vasodilator with a short duration of action, minimal and transient systemic hemodynamic effects, and ease of administration [1].

Clinical trial: Previous study investigated the magnitude and duration of the effect of regadenoson on CBF velocity in humans. Results demonstrated that regadenoson produced a dose-dependent increase in duration of CBF velocity augmentation. At all dose levels, regadenoson caused a rapid increase in CBF velocity that was near peak within 30 seconds of the bolus delivery. Regadenoson was generally well tolerated, and side effects at all doses were infrequent, mild, and self-limited [1].

Reference:
[1] Cerqueira MD.? The future of pharmacologic stress: selective A2A adenosine receptor agonists. Am J Cardiol. 2004 Jul 22;94(2A):33D-40D; discussion 40D-42D.