Sl. Cruz et al., Effects of volatile solvents on recombinant N-methyl-D-aspartate receptorsexpressed in Xenopus oocytes, BR J PHARM, 131(7), 2000, pp. 1303-1308
1 We have previously shown that toluene dose-dependently inhibits recombina
nt N-methyl-D-aspartate (NMDA) receptors at micromolar concentrations. This
inhibition was rapid, almost complete and reversible. The NR1/2B combinati
on was the most sensitive receptor subtype tested with an IC50 value for to
luene of 0.17 mM.
2 We now report on the effects of other commonly abused solvents (benzene,
m-xylene, ethylbenzene, propylbenzene. 1,1,1-trichlorethane (TCE) and those
of a convulsive solvent, 2,2,2-trifluororthyl ether (flurothyl), on NMDA-i
nduced currents measured in Xenopus oocytes expressing NR1/2A or NR1/2B rec
eptor subtypes.
3 All of the alkylbenzenes and TCE produced a reversible inhibition of NMDA
-induced currents that was dose- and subunit-dependent, The NR1/2B receptor
subtype was several times more sensitive to these compounds than the NR1/2
A subtype.
4 The convulsant solvent flurothyl had no effect on NMDA responses in oocyt
es but potently inhibited ion flux through recombinant GABA receptors expre
ssed in oocytes.
5 Overall, these results suggest that abused solvents display pharmacologic
al selectivity and that NR1/2B NMDA receptors may be an important target fo
r the actions of these compounds on the brain.