Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
FUNCTIONAL COMPARTMENTALIZATION OF ATP IS INVOLVED IN ANGIOTENSIN II-MEDIATED CLOSURE OF CARDIAC ATP-SENSITIVE K+ CHANNELS
Autore:
TSUCHIYA K; HORIE M; WATANUKI M; ALBRECHT CA; OBAYASHI K; FUJIWARA H; SASAYAMA S;
Indirizzi:
KYOTO UNIV,GRAD SCH MED,DIV CARDIAC ELECTROPHYSIOL,DEPT CARDIOVASC MED,SAKYO KU KYOTO 60601 JAPAN KYOTO UNIV,GRAD SCH MED,DIV CARDIAC ELECTROPHYSIOL,DEPT CARDIOVASC MED,SAKYO KU KYOTO 60601 JAPAN GIFU UNIV,FAC MED,DEPT INTERNAL MED 2 GIFU 500 JAPAN
Titolo Testata:
Circulation
fascicolo: 9, volume: 96, anno: 1997,
pagine: 3129 - 3135
SICI:
0009-7322(1997)96:9<3129:FCOAII>2.0.ZU;2-O
Fonte:
ISI
Lingua:
ENG
Soggetto:
PROTEIN-KINASE-C; POTASSIUM CHANNELS; VENTRICULAR MYOCYTES; PHOSPHOINOSITIDE METABOLISM; REPERFUSION ARRHYTHMIAS; CHLORIDE CONDUCTANCE; RECEPTORS; HEART; IDENTIFICATION; CALCIUM;
Keywords:
ANGIOTENSIN; ISCHEMIA; POTASSIUM CHANNELS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
50
Recensione:
Indirizzi per estratti:
Citazione:
K. Tsuchiya et al., "FUNCTIONAL COMPARTMENTALIZATION OF ATP IS INVOLVED IN ANGIOTENSIN II-MEDIATED CLOSURE OF CARDIAC ATP-SENSITIVE K+ CHANNELS", Circulation, 96(9), 1997, pp. 3129-3135

Abstract

Background The effects of angiotensin II (Ang II) on ATP-sensitive Kchannels (K-ATP) were investigated in ventricular myocytes enzymatically isolated from adult guinea pig heart. Methods and Results In the whole-cell and cell-attached configurations (including open-cell-attached mode) elf the patch-clamp technique, K-ATP currents (I-KATP) were activated through metabolic poisoning by the use of inhibitors of both glycolytic and oxidative ATP productions at 37 degrees C. In the whole-cell mode, I-KATP were reversibly suppressed by increasing extracellular glucose and Ang II (1 nmol/L). In the cell-attached mode, Ang II concentration-dependently inhibited single K-ATP activities with an IC50 value of 3.2+/-0.5 pmol/L (Hill coefficient=1.3+/-0.3). CV11974 (100nmol/L), an angiotensin 1 (AT(1)) receptor-selective antagonist, blocked the inhibitory action of Ang II. Preincubation of myocytes with pertussis toxin (5 mu g/mL for >120 min at 37 degrees C) virtually prevented subsequent Ang II action. The inhibitory effect of Ang II was also abolished in the open-cell-attached mode (achieved by a prior perfusion of streptolysin-O, 0.08 U/mL). In this mode, through tiny membraneholes, the intracellular ATP concentration can be controlled by bathing extracellular solutions containing a known ATP concentration. Conclusions The inhibitory actions of Ang II on K-ATP appear to be mediatedby an increase in the subsarcolemmal ATF concentration that results from the inhibition of adenylate cyclase activities via AT(1) receptors/PTX-sensitive G proteins.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 12/07/20 alle ore 13:04:04