Tissue-specific expression studies of Glutaryl-CoA dehydrogenase (Gcdh)
in adult rats revealed expression in the whole rat brain, almost exclusively
in neurons, and surprisingly high expression in the juxtamedullar cortex of
the kidney. The organic anion transporter 1 (OAT1) mediates basolateral
uptake of glutarate derivatives from proximal tubule cells and contributes
to their renal clearance. In brain, OAT1 is expressed at the choroid plexus,
in neurons of cortex and hippocampus. We hypothesized that Gcdh and
Oat1 are co-expressed in the same cells in kidney and brain and analyzed
their mRNA expression by in situ hybridization on cryosections of adult rat
brain, kidney and liver. In brain, Gcdh and Oat1 were found co-expressed
in most neurons. Only the Purkinje neurons of the cerebellum were found
to be Oat1 negative. In the kidney Gcdh and Oat1 are widely co-expressed
with a specific high expression in proximal tubule cells. In conclusion
there seems to be a functional coupling of Gcdh and Oat1 on a renal and
neuronal level. Further studies are ongoing to confirm these findings in
human tissues.