potassium chloride pretreatment did not change the character of the adrenoceptor agonist action of the agonists studied.7 since there is a similar prejunctional action at all distances from the ileocaecal valve and a different postjunctional effect of the adrenoceptor agonists at different distances from the ileocaecal junction , it could be suggested that in the guinea-pig ileum there are at least two alpha-adrenoceptors ( inhibitory prejunctional-alpha ( 2 ) , stimulatory postjunctional-alpha ( 1 ) ) , an inhibitory postjunctional beta-adrenoceptor and an as yet uncharacterized inhibitory postjunctional receptor.8 based on the specific postjunctional action of phenylephrine and the prejunctional action of ephedrine in the guinea-pig ileum , these drugs could be used with success as ; specific ' alpha ( 1 ) - and alpha ( 2 ) -adrenoceptor stimulants .
C0034784
alpha-adrenoceptors
C0001639
alpha ( 2