I-AB-MECA is iodinated form of parent compound - adenosine derivative, 4-aminobenzyl-5'-N-methylcarboxamidoadenosine (AB-MECA). AB-MECA i a potent agonist of adenosine A3 receptor agonist. 125I-labeled AB-MECA is widely used in in vitro pharmacological studies of adenosine A3 receptor as a refernece ligand. In addition I-AB-MECA is usefull in vitro autoradiography to map adenosine A3 receptor distribution tissues. I-AB-MECA bound to the rat adenosine A1 receptor and canine adenosine A2a receptor.