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Titolo:
Spermine and arcaine block and permeate N-methyl-D-aspartate receptor channels
Autore:
Araneda, RC; Lan, JY; Zheng, X; Zukin, RS; Bennett, MVL;
Indirizzi:
Yeshiva Univ Albert Einstein Coll Med, Dept Neurosci, Bronx, NY 10461 USA Yeshiva Univ Albert Einstein Coll Med Bronx NY USA 10461 nx, NY 10461 USA
Titolo Testata:
BIOPHYSICAL JOURNAL
fascicolo: 6, volume: 76, anno: 1999,
pagine: 2899 - 2911
SICI:
0006-3495(199906)76:6<2899:SAABAP>2.0.ZU;2-I
Fonte:
ISI
Lingua:
ENG
Soggetto:
CULTURED HIPPOCAMPAL-NEURONS; PROTEIN-KINASE-C; NMDA RECEPTOR; INWARD RECTIFICATION; POTASSIUM CHANNELS; STRUCTURAL DETERMINANTS; CYTOPLASMIC POLYAMINES; EXTRACELLULAR MG2+; CA2+ PERMEABILITY; SINGLE-CHANNEL;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
49
Recensione:
Indirizzi per estratti:
Indirizzo: Bennett, MVL Yeshivaronx, Albert Einstein Coll Med, Dept Neurosci, 1300 Morris Pk Ave, B Yeshiva Univ Albert Einstein Coll Med 1300 Morris Pk Ave Bronx NY USA 10461
Citazione:
R.C. Araneda et al., "Spermine and arcaine block and permeate N-methyl-D-aspartate receptor channels", BIOPHYS J, 76(6), 1999, pp. 2899-2911

Abstract

Polyamines such as spermine are thought to be endogenous regulators of NMDA (N-methyl-D-aspartate)-type glutamate receptors. Polyamine block of NMDA receptors was studied in excised outside-out patches from rat hippocampal neurons and Xenopus oocytes expressing recombinant receptors. Extracellular spermine and arcaine reduced NMDA single-channel conductance in a voltage-dependent manner, with partial relief of block evident at large inside negative membrane potentials. Reducing extracellular Nat concentration increasedthe apparent affinities for spermine and arcaine, indicating strong interaction between spermine and permeant ions. Internal spermine also blocked NMDA channels in a voltage-dependent manner, with relief of block evident at large inside positive potentials. The Woodhull model of channel block by animpermeant ion adequately described the actions of external spermine from -60 to +60 mV, but failed for more negative potentials. Eyring rate theory for a permeable blocker with two barriers and one binding site adequately described the voltage-dependent block and relief from block by both externaland internal spermine over the range of -120 to +60 mV. These findings indicate that polyamines block and permeate neuronal NMDA receptor channels from the extracellular and intracellular sides, although sensitivity to internal spermine is probably too low to be physiologically relevant.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/05/20 alle ore 14:32:55