nylon wool nonadherent cell populations were preincubated for 18 h in the presence of fetal bovine serum with and without methionine-enkephalin , leucine-enkephalin , dynorphin ( fragment 1-13 ) , [ d-ser2 ] -leucine-enkephalin-thr ( dslet ) , and [ d-ala2 , n me-phe4 , gly-ol5 ] -enkephalin ( dago ) .
C0014295
methionine-enkephalin
C0014298
enkephalin