the cyclic amp efflux from rat neostriatal slices induced by simultaneous activation of d-1 ( stimulatory ) and d-2 ( inhibitory ) dopamine receptors with 30 microm dopamine was inhibited by morphine ( 0.3-3 microm ) , [ d-ala2 , d-leu5 ] enkephalin ( dadle , 0.03-0.3 microm ) but not by [ d-pen2 , d-pen5 ] enkephalin ( dpdpe , 0.03-0.3 microm ) .
C0014298
enkephalin
C0525856
dpdpe