[Some features of enkephalin metabolism in the rat brain after administration of bestatin]

The effect of a single bestatin dose on enkephalin content, activities of enkephalin convertase, enkephalinase A and aminopeptidases as well as on the level of specific binding of (3H) (D-Ala-2,D-Leu-5)enkephalin in rat midbrain (including hypothalamus) and striatum has been studied. Using ANOVA and correlation analyses, the relationship between the changes in these parameters has been established. The different responses of the enkephalin system of rat brain seem to be due not only to differences in the ratios of the "enkephalinase" and "aminopeptidase" pathways of enkephalin catabolism but, also, to structural peculiarities of enkephalin-containing conduction tracts.