Functional expression of the organic cation/carnitine transporter 2 in rat astrocytes

摘要: In this study, we sought to identify the transporters that mediate uptake of L-carnitine and acetyl-L-carnitine in cultured rat cortical astrocytes. L-[(3)H]carnitine acetyl-L-[(3)H]carnitine were both saturable, mediated by a single Na(+)-dependent transport system. Uptake was inhibited L-carnitine, D-carnitine, various organic cations. Acylcarnitines (acetyl-, butyryl-, hexanoyl-, octanoyl- palmitoyl-L-carnitine) also interacted with transport. 2-Amino-2-norbornane carboxylic acid, known inhibitor amino acid transporter B(0,+) (ATB(0,+)), did not cause any significant inhibition. A highly correlation found between potencies acylcarnitines inhibition acyl chain length acylcarnitines. The expression mRNA for cation/carnitine (OCTNs), carnitine 2 (CT2) ATB(0,+) astrocytes investigated reverse transcription (RT)-PCR. OCTN2 expressed astrocytes, whereas OCTN1, OCTN3 CT2 could be detected. at very low levels Western blotting analysis indicated anti-OCTN2 polyclonal antibody recognized band 70 kDa kidney astrocyte preparations. immunoreactivity detected immunocytochemical staining. Inhibition RNA interference significantly into These results suggest is functionally responsible these cells.