Localization of 5-oxo-L-prolinase mRNA in the murine choroid plexus by in situ hybridization

The gamma-glutamyl cycle is thought to play a significant role in the trans port of amino acids between the blood and the cerebrospinal fluid. In the p resent study we investigated the expression of 5-oxo-L-prolinase, an enzyme of this pathway, in mouse brain and kidney by in situ hybridization using digoxygenin-labeled RNA probes. Expression of 5-OPase mRNA was found in epi thelial cells of the proximal tubules in kidney as well as in the epitheliu m and vascular endothelial cells of the choroid plexus but not in periventr icular capillaries. (C) 1999 Elsevier Science Ireland Ltd. All rights reser ved.