the non-selective alpha-adrenoceptor antagonist phentolamine and the selective alpha 1-adrenoceptor antagonist prazosin both inhibited the noradrenaline-induced elevation of radioiodine levels , whereas the alpha 2-adrenoceptor antagonist yohimbine had no such effect , except at a high dose level .
C0034784
alpha-adrenoceptor
C0001639
alpha