Background current in sino-atrial node cells of the rabbit heart.
نویسندگان
چکیده
منابع مشابه
Sino-atrial reciprocation in the isolated rabbit heart.
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...
متن کاملCurrent-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 ...
متن کاملFacilitation of the L-type calcium current in rabbit sino-atrial cells: effect on cardiac automaticity.
OBJECTIVE The L-type Ca(2+) current (I(Ca,L)) contributes to the generation and modulation of the pacemaker action potential (AP). We investigated facilitation of I(Ca,L) in sino-atrial cells. METHODS Facilitation was studied in regularly-beating cells isolated enzymatically from young albino rabbits (0.8-1 kg). We used the whole-cell patch-clamp technique to vary the frequency of the test de...
متن کاملInhibition by genistein of the hyperpolarization-activated cation current in porcine sino-atrial node cells.
1 The hyperpolarization-activated cation current (If) was recorded in single pacemaker cells of the porcine sino-atrial node, and the effects of genistein, an isoflavone inhibitor of tyrosine-specific protein kinases was investigated by the whole-cell patch clamp technique. 2 Genistein (20-500 microM) decreased If in a dose-dependent manner with an IC50 value of 62.3 microM and a maximum inhibi...
متن کاملPacemaker mechanism of porcine sino-atrial node cells.
In cardiac sino-atrial node (SAN) cells, time- and voltage-dependent changes in the gating of various ionic currents provide spontaneous, stable and repetitive firing of action potentials. To address the ionic nature of the species-dependent heart rate, action potentials and membrane currents were recorded in single cells dissociated from the porcine SAN, and compared with those from SAN cells ...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1992
ISSN: 0022-3751
DOI: 10.1113/jphysiol.1992.sp019029