competition for binding in both instances is stereoselective . l-phenylephrine has similar potencies in inhibiting ( 3h ) prazosin and ( 3h ) yohimbine specific binding whilst the imidazoline related partial alpha adrenergic agonists clonidine and guanfacine are more potent in inhibiting ( 3h ) yohimbine specific binding .
C1449836
imidazoline
C0009014
clonidine