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Tuned calcium entry through voltage-gated calcium channels is a key requirement for many cellular functions. This is ensured by channel gates which open during membrane depolarizations and seal the pore at rest. The gating process is determined by distinct sub-processes: movement of voltage-sensing domains (charged S4 segments) as well as opening and ...
Hering, S.+5 more
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Calcium Channel Blockers [PDF]
KEY POINTS AND PRACTICAL RECOMMENDATIONS: • Calcium channel blockers, which dilate arteries by reducing calcium flux into cells, effectively lower blood pressure, especially in combination with other drugs, and some formulations of agents of this class are approved for treating angina or cardiac dysrhythmias.
William J. Elliott, C. Venkata S. Ram
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Presynaptic calcium channels [PDF]
Presynaptic Ca2+ entry occurs through voltage-gated Ca2+ (CaV) channels which are activated by membrane depolarization. Depolarization accompanies neuronal firing and elevation of Ca2+ triggers neurotransmitter release from synaptic vesicles. For synchronization of efficient neurotransmitter release, synaptic vesicles are targeted by presynaptic Ca2 ...
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Calcium channels in lymphocytes [PDF]
On B and T lymphocytes, ligation of the antigen receptor (AgR) induces a biphasic Ca2+ response. In the initial phase there is a large elevation in the intracellular Ca2+ concentration as a consequence of Ca2+ release from intracellular stores. This is followed by a lower, but prolonged elevation that is dependent on extracellular Ca2+.1,2 This simple ...
Leanne Thwaite, Gillian Grafton
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In this review article, we discuss the different gene products and translational variants of ORAI proteins and their contribution to the makeup of different native calcium-conducting channels with distinct compositions and modes of activation. We also review the different modes of regulation of these distinct calcium channels and their impact on ...
James W. Putney, Mohamed Trebak
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Activation of Calcium Channels
Activation of Ca channels has been described as a Hodgkin-Huxley process in which the time constants have ratios of two or greater (1, 2, 3) or as a three-state linear sequential process with two very different time constants (4). We examined activation by measuring the turn-on and turn-off of macroscopic Ca currents and the discharge of single Ca ...
Arthur Brown+2 more
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Overdose of calcium channel blockers is potentially lethal. Verapamil and diltiazem are much more dangerous than dihydropyridines. Hypotension with (verapamil and diltiazem) or without (dihydropyridines) heart block and bradycardia are the most important features.
Ian M Whyte+5 more
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Mitogens and Calcium Channels [PDF]
Mitogens and, in particular, growth factors can induce changes in free intracellular Ca2+ concentration by opening voltage-independent cationic channels, with different degrees of Ca2+ selectivity. Recent work has provided preliminary insights into the nature of these channels and their role in the control of cell cycle progression.
LOVISOLO, Davide+3 more
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We propose a model of calcium channels that can explain most of their observed properties, including the anomalous mole fraction effect and mutation of the glutamate residues. The structure grossly resembles that of the KcsA potassium channel except for the presence of an extracellular vestibule and a shorter selectivity filter containing four ...
Corry, Ben+3 more
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Calcium channels for endocytosis [PDF]
Exocytosis and endocytosis need to be tightly balanced to keep cell surface area constant. This is of particular relevance for presynaptic terminals, where endocytosis needs to compensate for the ongoing exocytosis of synaptic vesicle to ultimately guarantee reliable synaptic transmission.
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