Modulation of single hyperpolarization-activated channels (i(f)) by cAMP in the rabbit sino-atrial node.
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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 ...
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 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 کاملI(f)-dependent modulation of pacemaker rate mediated by cAMP in the presence of ryanodine in rabbit sino-atrial node cells.
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...
متن کاملHyperpolarization-activated cyclic nucleotide-gated channels and cAMP-dependent modulation of exocytosis in cultured rat lactotrophs.
Hormone and neurotransmitter release from vesicles is mediated by regulated exocytosis, where an aqueous channel-like structure, termed a fusion pore, is formed. It was recently shown that second messenger cAMP modulates the fusion pore, but the detailed mechanisms remain elusive. In this study, we asked whether the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, which are a...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1994
ISSN: 0022-3751
DOI: 10.1113/jphysiol.1994.sp020038