text: Radioligand binding studies with the nonselective << alpha 1-adrenoceptor >> antagonist radioligand [[ 125I-BE2254 ]] showed that 73-87% of the binding sites in rabbit aorta are CEC sensitive and they are predominantly low affinity sites both for WB4101 (pKd = 8.1) and for 5-methylurapidil (pKd = 7.1).