Activation of f-channels by cAMP analogues in macropatches from rabbit sino-atrial node myocytes
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چکیده
منابع مشابه
Current-dependent Block of Rabbit Sino-Atrial Node If Channels by Ivabradine
"Funny" (f-) channels have a key role in generation of spontaneous activity of pacemaker cells and mediate autonomic control of cardiac rate; f-channels and the related neuronal h-channels are composed of hyperpolarization-activated, cyclic nucleotide-gated (HCN) channel subunits. We have investigated the block of f-channels of rabbit cardiac sino-atrial node cells by ivabradine, a novel heart ...
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I(f) contributes to generation and autonomic control of spontaneous activity of cardiac pacemaker cells through a cAMP-dependent, Ca(2+)-independent mechanism of rate regulation. However, disruption of Ca(2+) release from sarcoplasmic reticulum (SR) by ryanodine (Ry) has been recently shown to slow spontaneous rate and inhibit beta-adrenergic receptor (betaAR)-induced rate acceleration, leading...
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1. The effects of nizofenone fumarate were studied on the membrane potentials and currents of rabbit sino-atrial node preparations by means of the double-microelectrode voltage clamp method. 2. In spontaneously firing pacemaker cells, nizofenone (above 1 microM) decreased the heart rate. Above 3 microM, nizofenone reduced the maximum upstroke velocity, the amplitude of the action potential and ...
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In one patient reprodncibk episodes of sMal tachyear(200 msec, control; 70 msec, atropine) and sustained dia conld be elicited via programmed atrial premature atrial tachycardia no longer could be elicited. These dcpoluizations. Evllodion of the elechpphysiologic studies mpport the concept that h a t t i a l reciprocation shldks suggested that the most tikely mechanism was can be a mechanism re...
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Reciprocal beats between sinus node and atrium were studied in isolated rabbit heart tissue by microelectrode techniques. Early premature atrial responses which entered the sinus node frequently emerged to re-excite the atrium as "echoes." When the premature atrial beats discharged some but not all nodal areas, the atrial echoes, in turn, appeared to re-enter the sinus node. Repetitive reciproc...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1997
ISSN: 0022-3751
DOI: 10.1111/j.1469-7793.1997.565bm.x