The sustained inward current and inward rectifier K + current in pacemaker cells dissociated from rat sinoatrial node
نویسندگان
چکیده
منابع مشابه
Sustained inward current during pacemaker depolarization in mammalian sinoatrial node cells.
Several time- and voltage-dependent ionic currents have been identified in cardiac pacemaker cells, including Na(+) current, L- and T-type Ca(2+) currents, hyperpolarization-activated cation current, and various types of delayed rectifier K(+) currents. Mathematical models have demonstrated that spontaneous action potentials can be reconstructed by incorporating these currents, but relative con...
متن کاملIon selectivity and current saturation in inward-rectifier K+ channels
We investigated the features of the inward-rectifier K channel Kir1.1 (ROMK) that underlie the saturation of currents through these channels as a function of permeant ion concentration. We compared values of maximal currents and apparent K(m) for three permeant ions: K(+), Rb(+), and NH(4)(+). Compared with K(+) (i(max) = 4.6 pA and K(m) = 10 mM at -100 mV), Rb(+) had a lower permeability, a lo...
متن کاملA rapidly activating delayed rectifier K+ current regulates pacemaker activity in adult mouse sinoatrial node cells.
We have investigated the physiological role of the "rapidly activating" delayed rectifier K+ current (IKr) in pacemaker activity in isolated sinoatrial node (SAN) myocytes and the expression of mouse ether-a-go-go (mERG) genes in the adult mouse SAN. In isolated, voltage-clamped SAN cells, outward currents evoked by depolarizing steps (greater than -40 mV) were strongly inhibited by the class I...
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Cardiac conduction disorders are common diseases which cause slow heart rate and syncope. The best way to treat these diseases by now is to implant electronic pacemakers, which, yet, have many disadvantages, such as the limited battery life and infection. Biopacemaker has been expected to replace the electronic devices. Automatic ventricular myocytes (VMs) could show pacemaker activity, which w...
متن کاملMicrovascular endothelial cells from human omentum lack an inward rectifier K+ current.
In most macrovascular endothelial cell (EC) preparations, resting membrane potential is determined by the inwardly rectifying K+ current (I(K1)), whereas in microvascular EC the presence of I(K1) varies markedly. Cultured microvascular EC from small vessels of human omentum were examined by means of the voltage-clamp technique to elucidate the putative role of I(K1) in maintaining resting membr...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 2000
ISSN: 0022-3751,1469-7793
DOI: 10.1111/j.1469-7793.2000.t01-2-00593.x