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Titolo:
Gadolinium suppresses stretch-induced increases in the differences in epicardial and endocardial monophasic action potential durations and ventricular arrhythmias in dogs
Autore:
Takagi, S; Miyazaki, T; Moritani, K; Miyoshi, S; Furukawa, Y; Ito, S; Ogawa, S;
Indirizzi:
Keio08282, Sch Med, Dept Internal Med, Cardiopulm Div,Shinjuku Ku, Tokyo 16 Keio Univ Tokyo Japan 1608282 Med, Cardiopulm Div,Shinjuku Ku, Tokyo 16
Titolo Testata:
JAPANESE CIRCULATION JOURNAL-ENGLISH EDITION
fascicolo: 4, volume: 63, anno: 1999,
pagine: 296 - 302
SICI:
0047-1828(199904)63:4<296:GSSIIT>2.0.ZU;2-#
Fonte:
ISI
Lingua:
ENG
Soggetto:
MECHANOELECTRICAL FEEDBACK; ION CHANNELS; MYOCARDIUM; HEART; CELLS;
Keywords:
acute pressure overloading; dispersion of repolarization; mechano-electrical feedback; reentrant arrhythmias; stretch-activated channels;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
22
Recensione:
Indirizzi per estratti:
Indirizzo: Takagi, S Keionomachi,ch Med, Dept Internal Med, Cardiopulm Div,Shinjuku Ku, 35 Shina Keio Univ 35 Shinanomachi Tokyo Japan 1608282 juku Ku, 35 Shina
Citazione:
S. Takagi et al., "Gadolinium suppresses stretch-induced increases in the differences in epicardial and endocardial monophasic action potential durations and ventricular arrhythmias in dogs", JPN CIRC J, 63(4), 1999, pp. 296-302

Abstract

We tested whether acute pressure overloading of the left ventricle (LV) had spatially different effects on repolarization, thereby causing arrhythmias. The effects of gadolinium (Gd3+), a nonspecific blocker of stretch-activated channels were also examined. In anesthetized dogs, 5 s clamping of theascending aorta (AC), separated by 5-min intervals, was repeated while monophasic action potentials (MAPs) were recorded from the LV endocardium and epicardium. Gd3+ was injected into the left atrium before the second (500 mu mol) and third AC (2500 mu mol) (n=10). In a separate group (n=7), the effects of Gd3+ in the presence of verapamil were examined. Epicardial MAP durations at 50% and 90% repolarization (APD50; APD90) shortened in response to LV pressure rise and elongation of the segment length induced by the first AC, whereas endocardial MAP durations remained unchanged. Thus, the difference in APD50 and APD90 increased. Consistent with these changes, premature ventricular contractions (PVCs) developed. Gd3+ had no effect on baseline MAP durations, however it prevented an AC-induced increase in the difference by suppressing epicardial MAP shortening. Gd3+ also reduced PVCs in a dose-dependent manner at plasma concentrations of 1-4 mu mol/L. The effects were also evident after administration of verapamil. Thus, gadolinium suppressed an increase in the spatial dispersion of repolarization and arrhythmias via a mechanism of action different from that of verapamil.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 24/11/20 alle ore 22:01:17