the relative order of potency for the twelve agonists at prejunctional alpha 2-adrenoreceptors mediating inhibition of field-stimulation-induced contractions in the prostatic segment of the vas deferens was : clonidine greater than ( - ) -adrenaline greater than xylazine greater than or equal to ( - ) -noradrenaline greater than ( + ) -adrenaline greater than dopamine greater than or equal to phenylephrine greater than or equal to metaraminol greater than or equal to ( + ) -noradrenaline greater than ( - ) -isoprenaline greater than methoxamine greater than ( + ) -isoprenaline .
C0014563
adrenaline
C0028351
noradrenaline