the fact that this vasoconstriction was sensitive to the selective a1-receptor antagonist 8- ( 2-amino-4-chlorophenyl ) -1,3-dipropylxanthine ( pacpx ) and that the order of potency of agonists for this effect was l-pia greater than 2-chloroadenosine greater than d-pia greater than n6-ethylcarboxamide adenosine ( neca ) was consistent with activation of vascular a1-purinoceptors .
C0597357
antagonist
C0034836
purinoceptors