| Abstract: | In order to elucidate the role of aminopeptidases in enkephalin catabolism in rat brain, the local distribution of two types of cerebral cellular membrane aminopeptidases (puromycin-sensitive and puromycin-insensitive ones) and of the enkephalin system marker, enkephalinase A, was studied. It was found that the distribution patterns of the former enzymes differ essentially from that of enkephalinase A. Study of coupling between the enzymatic activities in different regions of rat brain revealed a strong correlation between the activities of puromycin-insensitive aminopeptidase and enkephalinase A in midbrain (including hypothalamus). It was supposed that in midbrain the role of aminopeptidase M in intrasynaptic inactivation of enkephalins is much more conspicuous than in other regions of rat brain. The puromycin-sensitive aminopeptidase activity does not seem to play a role in enkephalin catabolism. |
