methionine enkephalin , leucine enkephalin , [ d-ala2 , d-leu5 ] enkephalin , alpha-neoendorphin , beta-endorphin , dynorphin ( 1-13 ) and ethylketocyclazocine inhibited the contractions of rabbit ear artery ring segments elicited by transmural nerve stimulation at 8 hz .
C0014295
methionine enkephalin
C0014298
enkephalin