Cirazoline hydrochloride is a synthetic compound that acts as a competitive full agonist of the α1A-adrenergic receptor (α1A-AR) with a binding affinity of Ki = 120 nM, and Cirazoline hydrochloride also functions as a partial agonist at α1B-AR (Ki = 960 nM) and α1D-AR (Ki = 660 nM), thereby serving as a versatile adrenergic receptor probe with relevance for studying vascular tone regulation, adrenergic pharmacology, and potential therapeutic cardiovascular applications.

AR-α1A:120 nM (Ki), AR-α1D:660 nM (Ki), AR-α1B:960 nM (Ki)