Bilirubin (B) inhibits glutamate (G) and dopamine (D) uptake in isolated presynaptic vesicles (PV). † 901
| Autor: | Thor Wr Hansen, S. Ivar Walaas, Svein Roseth, Frode Fonnum |
|---|---|
| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Pediatric Research. 41:153-153 |
| ISSN: | 1530-0447 0031-3998 |
| DOI: | 10.1203/00006450-199704001-00920 |
| Popis: | Background B is a well known neurotoxic agent and has been shown to affect neurotransmitter metabolism in nerve terminals. However, the level and mechanism of such effects are not clear. Here we show for the first time that B directly affects neurotransmitter metabolism in isolated PV. Materials and methods PV were isolated from rat brains by centrifugation in sucrose gradients. PV (0.02 mg protein) were preincubated for 15 min at 30°C +/- B (0-100 μM), followed by addition of either 1 mM L-[3H]G or 83 nM [3H]D with 2 mM ATP. Incubation was continued for 3 min and stopped by adding ice-cold 0.15 M KCl, followed by filtration through Millipore HAWP filters. These were washed again x2 with 0.15 M KCl before scintillation counting. Effects on Δ-pH were investigated by measuring the uptake of [14C]methylamine in the presence of 4 mM MgSO4, 140 mM KCl, 25 μM methylamine, 20 μg PV protein, and 2 mM ATP. After incubation for 2-10 min at 30 or 0°C (+/- 100μM B), the reaction was stopped by adding 0.15 M ice-cold KCl. Non-specific uptake of methylamine was measured by adding 200 nM of the specific ATPase inhibitor Bafilomycin A. Results B inhibited vesicular uptake of both G and D starting at 75 μM B (p |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|