the relaxation induced by isoprenaline was antagonized by propranolol , and the effects of noradrenaline and ephedrine by yohimbine.8 it is concluded that in the guinea-pig ileum there are postsynaptic beta-adrenoceptors and at least two types of alpha-adrenoceptors : alpha ( 1 ) -excitatory postjunctional adrenoceptors activated by phenylephrine , noradrenaline and adrenaline and antagonized by phenoxybenzamine , carbidine and phentolamine ;
C0028351
noradrenaline
C0014563
adrenaline