binding was stereoselective with regard to the ( - ) -isomer of noradrenaline and the order of potency for displacement of [ 3h ] -guanfacine by agonists was naphazoline greater than clonidine greater than ( - ) -adrenaline greater than ( - ) -alpha methylnoradrenaline greater than ( - ) -noradrenaline greater than ( +/- ) -alpha-methylnoradrenaline greater than ( + ) -noradrenaline greater than methoxamine greater than ( + ) -adrenaline greater than phenylephrine and by antagonists was phentolamine greater than dihydroergocryptine greater than piperoxane greater than yohimbine greater than prazosin greater than labetalol greater than indoramin suggested binding to alpha 2-adrenoceptors .
C0028351
noradrenaline
C0014563
adrenaline