Effect of in vivo striatal perfusion of lipopolysaccharide on dopamine metabolites.

We have used the microdialysis technique to perfuse different concentrations of LPS in the rat's striatum 24h after the implantation of a microdialysis probe. Dopamine metabolites in the dialysate obtained from the rat brain were measured by HPLC using electrochemical detection. Results show that intrastriatal perfusion of different concentrations of LPS produced a dose-dependent decrease in the extracellular DOPAC output, with no effect on the extracellular HVA output. Since DOPAC levels reflect the intraneuronal metabolism of dopamine while and HVA levels reflect the extraneuronal one, we suggest that in vivo intrastriatal LPS perfusion especially affects the level of newly synthesized dopamine or intraneuronal dopamine catabolism.