for characterisation in vitro , four parallel assays were used : the guinea-pig ileum and mouse vas deferens as pharmacological models at 36 degrees c and the inhibition of binding of [ 3h ] -naltrexone , [ 3h ] -leucine-enkephalin and [ 3h ] -methione-enkephalin at 0 degrees c .
C0014294
leucine-enkephalin
C0014298
enkephalin