dampgo ( tyr-d-ala2-gly-nmephe4-gly-ol5 ) , dpdpe ( d-pen2 , d-pen5 , enkephalin ) and u50-488h , opioid agonists highly selective for mu , delta and kappa receptors , respectively , were administered alone i.c.v . or intrathecally ( i.t . ) or in combination ( i.c.v . plus i.t . ) to determine ed50 values for the tail-flick response in mice .
C0525856
dpdpe
C0014298
enkephalin