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Mechanisms of AMPA Receptor Inhibition by Diminazene
Diminazene is an anti-infection agent for animals and is a member of the diarylamidine group. This study reports the first detection of its inhibitory effect on AMPA-type ionotropic glutamate receptors. Experiments were carried out on isolated Wistar rat neurons: striatal giant cholinergic interneur...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer International Publishing
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8930484/ https://www.ncbi.nlm.nih.gov/pubmed/35317269 http://dx.doi.org/10.1007/s11055-022-01238-y |
Sumario: | Diminazene is an anti-infection agent for animals and is a member of the diarylamidine group. This study reports the first detection of its inhibitory effect on AMPA-type ionotropic glutamate receptors. Experiments were carried out on isolated Wistar rat neurons: striatal giant cholinergic interneurons were used to study calcium-permeable AMPA receptors and hippocampal field CA1 pyramidal neurons were used to study calcium-impermeable AMPA receptors. Cells were isolated by vibrodissociation and currents were recorded by voltage clamping in the whole cell configuration. Diminazene produced concentration-dependent inhibition of currents evoked by application of kainate in both neuron types. IC(50) values for calcium-permeable and calcium-impermeable AMPA receptors were 60 ± 11 and 160 ± 30 μM, respectively. Of note is that the inhibitory action of diminazene increased with increases in agonist concentration. The plot of the voltage dependence of inhibition at a fixed diminazene concentration for calcium-permeable AMPA receptors was biphasic: minimal inhibition was seen at positive potentials and maximum at –40 to –60 mV, while further hyperpolarization produced a gradual decrease in blockade efficacy. All these properties provide evidence that diminazene blocks AMPA receptor channels, perhaps with penetration through channels into cells. |
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