Modulation by intracellular Ca2+ of the hyperpolarization-activated inward current in rabbit single sino-atrial node cells.
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چکیده
منابع مشابه
Inhibition 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 کاملHyperpolarization-Activated Current, If, in Mathematical Models of Rabbit Sinoatrial Node Pacemaker Cells
A typical feature of sinoatrial (SA) node pacemaker cells is the presence of an ionic current that activates upon hyperpolarization. The role of this hyperpolarization-activated current, If, which is also known as the "funny current" or "pacemaker current," in the spontaneous pacemaker activity of SA nodal cells remains a matter of intense debate. Whereas some conclude that If plays a fundament...
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 کاملCharacterization of a hyperpolarization-activated inward current in Cajal-Retzius cells in rat neonatal neocortex.
Cajal-Retzius cells are among the first neurons appearing during corticogenesis and play an important role in the establishment of cortical lamination. To characterize the hyperpolarization-activated inward current (I(h)) and to investigate whether I(h) contributes to the relatively positive resting membrane potential (RMP) of these cells, we analyzed the properties of I(h) in visually identifi...
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...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1989
ISSN: 0022-3751
DOI: 10.1113/jphysiol.1989.sp017488