SOME FEATURES OF ENKEPHALIN METABOLISM IN RAT-BRAIN FOLLOWING ADMINISTRATION OF BESTATIN

The effect of a single administration of bestatin on the content of en kephalins, the activities of enkephalin convertase, enkephalinase A, a nd aminopeptidases, and the level of specific binding of [H-3](D-Ala-2 ,D-Leu-5) enkephalin in rat midbrain (including hypothalamus) and stri atum is described Dispersion and correlation analyses were used to sho w the relationship between the changes in these parameters. The differ ent responses of the enkephalin system in brain compartments seem to b e due not only to differences in the ratios of the ''enkephalinase'' a nd ''aminopeptidase'' pathways of enkephalin catabolism, but also to s tructural peculiarities of enkephalin-containing conduction tracts.