Is inhibition of dopamine uptake relevant to the hypnotic action of i.v. anaesthetics?

Br J Anaesth. 1996 Aug;77(2):254-6. doi: 10.1093/bja/77.2.254.

Abstract

We have examined the effects of ketamine, etomidate, propofol and thiopentone on the uptake of [3H]-dopamine into rat striatal synaptosomes. [3H]-dopamine uptake (5 min, 37 degrees C) was potently inhibited by nomifensine, a classical inhibitor of the dopamine carrier. All anaesthetics induced concentration-related inhibition of the uptake process, values for IC50 being 4.6 x 10(-6), 5.5 x 10(-5), 1.5 x 10(-4) and 2.7 x 10(-4) mol litre-1 for ketamine, etomidate, propofol and thiopentone, respectively. For all anaesthetics, inhibition of [3H]-dopamine uptake was reversible with a non-competitive profile. These data suggest that inhibition of striatal dopamine uptake may represent a relevant target site for some, but not all, i.v. anaesthetics.

MeSH terms

  • Anesthetics, Intravenous / pharmacology*
  • Animals
  • Dopamine / metabolism*
  • Dose-Response Relationship, Drug
  • Etomidate / pharmacology
  • Ketamine / pharmacology
  • Male
  • Propofol / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Synaptosomes / drug effects*
  • Synaptosomes / metabolism*
  • Thiopental / pharmacology

Substances

  • Anesthetics, Intravenous
  • Ketamine
  • Thiopental
  • Dopamine
  • Propofol
  • Etomidate