Abstract (EN):
The aim of this work was to characterize the uptake of 1-methyl-4-phenylpyridinium (MPP+) in the JAR human choriocarcinoma cell line. As JAR cells, as well as the placenta, express the neuronal serotonin transporter (SERT), a comparison between the uptake of H-3-MPP+ and H-3-serotonin (H-3-5HT) was made. Specific uptake of H-3-MPP+ (0.2 mum) was temperature-, Na+- and potential-dependent. 5HT and MPP+ reduced H-3-MPP+ specific uptake (for 5HT, its IC50 was found to be 4 mum). The SERT inhibitors desipramine and fluoxetine also inhibited H-3-MPP+ specific uptake (with IC50S of 189 and 0.92 mum, respectively). The inhibitors of the extraneuronal monoamine transporter (EMT) and of the organic cation transporter type 2 (OCT2), corticosterone and decynium22, had no effect on H-3-MPP+ specific uptake, but cyanine863 concentration-dependently reduced it (with an IC50 of 23 mum). Specific uptake of H-3-5HT (0.2 mum) by JAR cells was temperature-, Na+- and potential-dependent. 5HT, MPP+, desipramine and fluoxetine concentration-dependently inhibited H-3-5HT specific uptake (with IC50S of 1-9 muM ,50 mum, 0. 17 mum and 0.046 mum, respectively). Corticosterone showed no effect, but decynium22 and cyanine863 significantly reduced 3 H-5HT specific uptake. For cyanine863, its IC50 was found to be 11 mum. In conclusion, the results suggest that: (1) uptake of H-3-5HT by JAR cells occurs exclusively through SERT; (2) uptake of H-3-MPP+ by JAR cells involves SERT and also another transporter; (3) neither EMT nor OCT2 are functionally present in JAR cells.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
9