Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
The triakontatetraneuropeptide TTN increases [Ca2+](i) in rat astrocytes through activation of peripheral-type benzodiazepine receptors
Autore:
Gandolfo, P; Louiset, E; Patte, C; Leprince, J; Masmoudi, O; Malagon, M; Gracia-Navarro, F; Vaudry, H; Tonon, MC;
Indirizzi:
Univ Rouen, UA CNRS, INSERM U413,European Inst Peptide Res, Lab Cellular &Mol Neuroendocrinol, F-76821 Mont St Aignan, France Univ Rouen Mont St Aignan France F-76821 F-76821 Mont St Aignan, France Univ Cordoba, Dept Cellular Biol & Immunol, Cordoba, Spain Univ Cordoba Cordoba Spain Dept Cellular Biol & Immunol, Cordoba, Spain
Titolo Testata:
GLIA
fascicolo: 2, volume: 35, anno: 2001,
pagine: 90 - 100
SICI:
0894-1491(200108)35:2<90:TTTI[I>2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
DIAZEPAM-BINDING INHIBITOR; OCTADECANEUROPEPTIDE ODN; CALCIUM CHANNELS; ENDOZEPINE TRIAKONTATETRANEUROPEPTIDE; HIPPOCAMPAL ASTROCYTES; CULTURED ASTROCYTES; PROCESSING PRODUCT; CYTOSOLIC CALCIUM; MESSENGER-RNA; ANION CHANNEL;
Keywords:
endozepines; L-type calcium channels; intracellular calcium concentration; astroglial cells;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
54
Recensione:
Indirizzi per estratti:
Indirizzo: Vaudry, H Univ Rouen, UA CNRS, INSERM U413,European Inst Peptide Res, Lab Cellular &Mol Neuroendocrinol, IFRMP 23, F-76821 Mont St Aignan, France Univ Rouen IFRMP 23 Mont St Aignan France F-76821 ignan, France
Citazione:
P. Gandolfo et al., "The triakontatetraneuropeptide TTN increases [Ca2+](i) in rat astrocytes through activation of peripheral-type benzodiazepine receptors", GLIA, 35(2), 2001, pp. 90-100

Abstract

Astrocytes synthesize a series of regulatory peptides called endozepines, which act as endogenous ligands of benzodiazepine receptors. We have recently shown that one of these endozepines, the triakontatetraneuropeptide TTN,stimulates DNA synthesis in astroglial cells. The purpose of the present study was to determine the mechanism of action of TTN on cultured rat astrocytes. Binding of the peripheral-type benzodiazepine receptor ligand [H-3]Ro5-4864 to intact astrocytes was displaced by TTN, whereas its C-terminal fragment (TTN[17-34], the octadecaneuropeptide ODN) did not compete for [H-3]Ro5-4864 binding. Microfluorimetric measurement of cytosolic calcium concentrations ([Ca2+](i)) with the fluorescent probe indo-1 showed that TTN (10(-10) to 10(-6) M) provokes a concentration-dependent increase in [Ca2+](i) in cultured astrocytes. Simultaneous administration of TTN (10(-8) M) and Ro5-4864 (10(-5) M) induced an increase in [Ca2+](i) similar to that obtained with Ro5-4864 alone. In contrast, the effects of TTN (10-8 M) and ODN (10(-8) M) on [Ca2+](i) were strictly additive. Chelation of extracellular Ca2 by EGTA (6 mM) or blockage of Ca2+ channels with Ni2+ (2 mM) abrogated the stimulatory effect of TTN. The calcium influx evoked by TTN (10(-7) M) orby Ro5-4864 (10(-5) M) was not affected by the N- and T-type calcium channel blockers co-conotoxin (10(-6) M) and mibefradil (10(-6) M), but was significantly reduced by the L-type calcium channel blocker nifedipine (10(-7) M). Patch-clamp studies showed that, at negative potentials, TTN (10(-7) M)induced a sustained depolarization. Reduction of the chloride concentration in the extracellular solution shifted the reversal potential from 0 mV toa positive potential. These data show that TTN, acting through peripheral-type benzodiazepine receptors, provokes chloride efflux, which in turn induces calcium influx via L-type calcium channels in rat astrocytes. (C) 2001Wiley-Liss, Inc.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/03/20 alle ore 15:44:09