Expression of PEPT2 peptide transporter mRNA and protein in glial cells ofrat dorsal root ganglia

The peptide-transporter PEPT2 mediates electrogenic uphill transport of di- and tripeptides, selected peptidomimetics and delta aminolevulinic acid. T he transporter was cloned from rat central nervous tissue recently and its mRNA was localized to astrocytes. In the present studies the expression of PEPT2-protein and -mRNA in rat dorsal root ganglia was investigated. Immuno histochemistry revealed PEPT2-immunoreactivity in satellite glial cells sur rounding the ganglionic neurons. There was no expression in neuronal cells. In-situ-hybridization studies colocalized the expression of PEPT2-mRNA to satellite cells. This is the fi rst report on the expression of PEPT2-prote in in the peripheral nervous system where PEPT2 may serve as uptake system for products of protein degradation, for removal of biologically active sho rt-chain peptides and non-peptides such as delta aminolevulinic acid. (C) 2 001 Elsevier Science Ireland Ltd. All rights reserved.