The effect of sevoflurane on the release of [3H]dopamine from rat brain cortical slices.
Dopamine is a neurotransmitter that exerts major control on important brain functions and some lines of studies suggest that dopaminergic neurotransmission may be a potential target for volatile anesthetics. In the present study, rat brain cortical slices were labeled with [(3)H]dopamine to investigate the effects of sevoflurane on the release of this neurotransmitter. [(3)H]dopamine release was significantly increased in the presence of sevoflurane (0.46 mM) and this effect was independent of extracellular or intracellular calcium. In addition, [(3)H]dopamine release evoked by sevoflurane was not affected by TTX (blocker of voltage-dependent sodium channels) or reserpine (a blocker of the vesicular monoamine transporter). These data suggest that the dopamine release induced by sevoflurane is non-vesicular, independent of exocytosis and, would be mediated by the dopamine transporter (DAT). GBR12909 and nomifensine, inhibitors of DAT, decreased the release of [(3)H]dopamine evoked by sevoflurane. The same effect was also observed when the brain cortical slices were incubated at low temperature and low extracellular sodium. Ouabain, a Na(+)/K(+) ATPase pump inhibitor, which is known to induce dopamine release through reverse transport, decreased [(3)H]dopamine release induced by sevoflurane. In conclusion, the present study suggests that sevoflurane increases [(3)H]dopamine release in brain cortical slices that is mediated by DAT located at the plasma membrane.
Silva
Janice H
JH
Department of Pharmacology, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
Gomez
Renato S
RS
Diniz
Paulo H C
PH
Gomez
Marcus V
MV
Guatimosim
Cristina
C
D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects*; D002614:Chelating Agents / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012110:Reserpine / Q000494:pharmacology; D000077149:Sevoflurane; D012964:Sodium / Q000494:pharmacology; D014316:Tritium / Q000378:metabolism
D018759:Adrenergic Uptake Inhibitors; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D008738:Methyl Ethers; D010975:Platelet Aggregation Inhibitors; D014316:Tritium; D000077149:Sevoflurane; D012110:Reserpine; D012964:Sodium; D004298:Dopamine