1. The effects of two @entity23218 derivatives, @entity35429 ( @entity35429 ) and @entity70142 ( @entity70142 ) on @entity4176 -induced currents were studied in @entity1238 oocytes expressing recombinant ionotropic @entity2227 receptors and in freshly isolated neurones from @entity35 hippocampal slices. 2. The @entity23218 derivatives caused use- and voltage-dependent block of open channels of recombinant @entity140 receptors. This antagonism was dependent on receptor subunit composition; channels gated by recombinant, homomeric @entity4860 and @entity18858 receptors exhibited a higher sensitivity to block than those gated by receptors containing edited @entity139 subunits. In the former cases, @entity35429 had an IC50 of 1.6 microM at a holding potential (Vh) of -80 mV and @entity70142 was 3.8 times less potent than @entity35429 . In contrast, 100 microM @entity35429 inhibited responses to 100 microM @entity4176 of receptors containing edited @entity139 subunits by only 7.8 +/- 2.4% (n = 5 oocytes at a Vh of -80 mV. 3. Native @entity140 / @entity4176 receptors in isolated hippocampal cells were inhibited by @entity23218 derivatives in a use- and voltage-dependent manner. This antagonism was dependent on cell type: pyramidal neurones were less sensitive to @entity35429 (IC50 = 1617 microM at Vh = -80 mV) than interneurones (IC50 = 1.6 microM at Vh = -80 mV). @entity35429 and @entity70142 were equipotent when applied to pyramidal neurones, but @entity70142 was less potent (approximately 3 times) than @entity35429 when applied to interneurones. 4. It is concluded that the presence of the edited @entity139 subunit in recombinant @entity140 receptors and native @entity140 / @entity4176 receptors inhibits channel block by organic cations and that @entity23218 derivatives are potentially valuable tools for identifying classes of @entity140 / @entity4176 receptors and their roles in synaptic transmission.

Block of open channels of recombinant @entity140 receptors and native XXXX / @entity4176 receptors by @entity23218 derivatives.

@entity2227 :: ('CHEBI:29987', 'Chemical') :: ['glutamate'] @entity1238 :: ('8355', 'Species') :: ['Xenopus'] @entity35429 :: ('MESH:C110702', 'Chemical') :: ['IEM-1460', '1-trimethylammonio-5-(1-adamantane-methyl-ammoniopentane dibromide)'] @entity4860 :: ('50592(Tax:10116)', 'Gene') :: ['GluR1'] @entity139 :: ('29627(Tax:10116)', 'Gene') :: ['GluR2'] @entity4176 :: ('MESH:D007608', 'Chemical') :: ['kainate'] @entity18858 :: ('29628(Tax:10116)', 'Gene') :: ['GluR3'] @entity140 :: ('MESH:D018350', 'Chemical') :: ['AMPA'] @entity35 :: ('10116', 'Species') :: ['rat'] @entity70142 :: ('MESH:C092754', 'Chemical') :: ['IEM-1754', '1-ammonio-5-(1-adamantane-methylammoniopentane dibromide)'] @entity23218 :: ('MESH:D000218', 'Chemical') :: ['adamantane']
@entity140 :: (MESH:D018350,Chemical) :: ['AMPA']
