Expression of endo-oligopeptidase A in the rat central nervous system: a non-radioactive in situ hybridization study

Endo-oligopeptidase A (EOPA, formerly EC 3.4.22.19), a thiol-activated olig opeptidase, is able to degrade both bradykinin and neurotensin. and also to convert enkephalin-containing peptides into enkephalins. The expression of this enzyme was studied in the rat brain by in situ hybridization using no n-radiotopic probes. The distribution of EOPA transcripts included many reg ions of the rat central nervous system, with higher expression in some regi ons, such as the hippocampus, cerebellum, and basal nucleus of Meynert. The marked EOPA expression in these areas could be anticipated. since they are rich in neuropeptides that are known to be EOPA substrates in vitro. The d ata characterize a widespread occurrence of EOPA in the rat brain and reinf orce the suggestion of a critical role for EOPA in peptide processing. (C) 2001 Elsevier Science B.V. All rights reserved.