Inhibition of hOCTN2-mediated carnitine uptake by organic cations
| Organic Cation | [3H]Carnitine Uptake | |
|---|---|---|
| pmol/106 cells/30 min | % | |
| Control | 3.02 ± 0.08 | 100 |
| Verapamil (0.05 mM) | 0.99 ± 0.12 | 33 |
| Verapamil (0.5 mM) | 0.02 ± 0.01 | 1 |
| Desipramine (0.05 mM) | 1.66 ± 0.30 | 55 |
| Desipramine (0.5 mM) | 0 | 0 |
| Cimetidine (2 mM) | 0.95 ± 0.02 | 32 |
| TEA (2 mM) | 1.21 ± 0.03 | 40 |
| MPTP (2 mM) | 1.43 ± 0.02 | 47 |
| Choline (2 mM) | 2.46 ± 0.04 | 82 |
| Guanidine (2 mM) | 2.95 ± 0.05 | 98 |
HRPE cells were transfected with hOCTN2 cDNA, and expression was accomplished by the vaccinia virus expression system. Cells transfected with vector alone were used as control for measurement of endogenous carnitine uptake in these cells. Only cDNA-specific uptake was used in data analysis. Uptake of [3H]carnitine (25 nM) was measured for 30 min in the presence of NaCl (pH 7.5). Organic cations were used at indicated concentrations. Values are means ± S.E.