[Ion channels of glutamate receptors of nerve-muscle junction of the fly larva Calliphora vicina demonstrate a high structural homology with vertebrate AMPA-channels].

In experiments on the nerve-muscle junction of the fly larva Calliphora vicina, regularities of the blocking action of organic cations on ion channels of glutamate postsynaptic receptors have been studied. In total, 26 compounds were studied. The following regularities of structural-functional relations have been revealed: 1) the channels are not blocked by monocation compounds; 2) bication derivatives block efficiently the channel with a certain distance between hydrophobic group and terminal amino group; 3) bication compounds with trimethylammonium terminal group are significantly more efficient than compounds with non-substituted amino group. All these regularities are characteristic of blockade of the AMPA channels, but not of the vertebrate type NMDA channels. Earlier it has been shown that differences in structural-functional relations during blockade of the AMPA and NMDA channels are determined by different location of the hydrophobic and hydrophilic components of the binding area as well as by different diameter of the channels. The fact that channels of the fly larva receptor demonstrate the same regularities of blockade as the vertebrate AMPA channels indicates their structural similarity that is a consequence of their high homology.