Intracellular spermine confers rectification on rat calcium-permeable AMPA and kainate receptors.
AUTOR(ES)
Kamboj, S K
RESUMO
1. Whole-cell recordings were made from cerebellar granule cells cultured in high-K+ medium to induce expression of Ca(2+)-permeable AMPA receptors. Current-voltage (I-V) plots of agonist-evoked responses showed varying degrees of inward rectification, but became linear within 5-10 min. 2. Recombinant Ca(2+)-permeable kainate receptors, composed of GluR6(Q)/KA-2 subunits, exhibited rectifying whole-cell I-V plots that became linear in outside-out patches. 3. Loss of rectification in granule cells was prevented by including 100 microM spermine in the pipette; the degree of rectification was then correlated with Ca2+ permeability. 4. Spermine also prevented loss of rectification in patches containing GluR6(Q)/KA-2 receptors (IC50, 1.7 microM). 5. We suggest that spermine, or a similar cellular constituent, may act as a cytoplasmic factor conferring inward rectification on Ca(2+)-permeable non-NMDA receptors, and that 'washout' of this factor underlies the observed loss of rectification.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1156521Documentos Relacionados
- Calcium-permeable AMPA/kainate receptors mediate toxicity and preconditioning by oxygen-glucose deprivation in oligodendrocyte precursors
- Blockade of calcium-permeable AMPA receptors protects hippocampal neurons against global ischemia-induced death
- ATP-activated inward current and calcium-permeable channels in rat macrophage plasma membranes.
- Block of native Ca(2+)-permeable AMPA receptors in rat brain by intracellular polyamines generates double rectification.
- Block of native Ca2+-permeable AMPA receptors in rat brain by intracellular polyamines generates double rectification