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Titolo:
Involvement of calmodulin in glucagon-like peptide 1(7-36) amide-induced inhibition of the ATP-sensitive K+ channel in mouse pancreatic beta-cells
Autore:
Ding, WG; Kitasato, H; Matsuura, H;
Indirizzi:
Shiga Univ Med Sci, Dept Physiol, Shiga 5202192, Japan Shiga Univ Med SciShiga Japan 5202192 ept Physiol, Shiga 5202192, Japan
Titolo Testata:
EXPERIMENTAL PHYSIOLOGY
fascicolo: 3, volume: 86, anno: 2001,
pagine: 331 - 339
SICI:
0958-0670(200105)86:3<331:IOCIGP>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
MUSCLE PHOSPHORYLASE-KINASE; B-CELLS; INSULIN-SECRETION; CA2+ CHANNEL; EXOCYTOSIS; ACTIVATION; INCRETIN; RECEPTOR; SUBUNIT; ANTAGONIST;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
35
Recensione:
Indirizzi per estratti:
Indirizzo: Ding, WG Shiga Univ Med Sci, Dept Physiol, Shiga 5202192, Japan Shiga UnivMed Sci Shiga Japan 5202192 ol, Shiga 5202192, Japan
Citazione:
W.G. Ding et al., "Involvement of calmodulin in glucagon-like peptide 1(7-36) amide-induced inhibition of the ATP-sensitive K+ channel in mouse pancreatic beta-cells", EXP PHYSIOL, 86(3), 2001, pp. 331-339

Abstract

The present investigation was designed to examine whether calmodulin is involved in the inhibition of the ATP-sensitive K+ (K-ATP) channel by glucagon-like peptide 1(7-36) amide (GLP-1) in mouse pancreatic beta -cells. Membrane potential, single channel and whole-cell currents through the K-ATP channels, and intracellular free Ca2+ concentration ([Ca2+](i)) were measured in single mouse pancreatic beta -cells. Whole-cell patch-clamp experiments with amphotericin-perforated patches revealed that membrane conductance at around the resting potential is predominantly supplied by the K-ATP channels in mouse pancreatic beta -cells. The addition of 20 nM GLP-1 in the presence of 5 mM glucose significantly reduced the membrane K-ATP conductance, accompanied by membrane depolarization and the generation of electrical activity. A calmodulin inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalenes (W-7,20 muM I) completely reversed the inhibitory actions of GLP-1 on the membrane K-ATP conductance and resultant membrane depolarization. Cell-attached patch recordings confirmed the inhibition of the K-ATP channel activity by 20 nM GLP-1 and its restoration by 20 muM W-7 or 10 muM calmidazolium at the single channel level. Bath application of 20 muM W-7 also consistently abolished the GLP-1-evoked increase in [Ca2+](i) in the presence of 5 mM glucose. These results strongly suggest that the mechanisms by which GLP-1 inhibits the K-ATP channel activity accompanied by the initiation of electricalactivity in mouse pancreatic beta -cells include a calmodulin-dependent mechanism in addition to the well-documented activation of the cyclic AMP-protein kinase A system.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 17/01/21 alle ore 18:28:01