morphine , etorphine , and several enkephalin analogs ( met-enkephalin , d-ala2-met-enkephalin , and d-met2 , pro5-enkephalinamide ) were capable of inhibiting the stimulation of ac produced by dopamine ( 90-100 % with etorphine or d-ala2-met-enkephalin ) .
C0014298
enkephalin
C0014295
met-enkephalin