Calcium channel

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview[edit | edit source]

A Calcium channel is an ion channel which displays selective permeabiltiy to calcium ions. It is sometimes synonymous as voltage-dependent calcium channel, although there are also ligand-gated calcium channels.

Comparison tables[edit | edit source]

The following tables explain gating, gene, location and function of different types of calcium channels, both voltage and ligand-gated.

Voltage-gated[edit | edit source]

Type	Gated by	Protein	Gene	Location	Function
L-type	high voltage	Ca_v1.1 Ca_v1.2 Ca_v1.3 Ca_v1.4	CACNA1S CACNA1C CACNA1D CACNA1F	Skeletal muscle, bone (osteoblasts), ventricular myocytes**, dendrites and dendritic spines of cortical neurones	SMC and cardiac muscle contraction ^[1]. Responsible for prolonged action potential in cardiac muscle.
P-type/Q-type	high voltage	Ca_v2.1	CACNA1A	Purkinje neurons in the cerebellum / Cerebellar granule cells	neurotransmitter release ^[1]
N-type	high voltage	Ca_v2.2	CACNA1B	Throughout the brain	neurotransmitter release ^[1]
R-type	intermediate voltage	Ca_v2.3	CACNA1E	Cerebellar granule cells, other neurons	?^[1]
T-type	low voltage	Ca_v3.1 Ca_v3.2 Ca_v3.3	CACNA1G CACNA1H CACNA1I	neurons, cells that have pacemaker activity, bone (osteocytes)	Regular sinus rhythm^[1]

Ligand-gated[edit | edit source]

the receptor-operated calcium channels (in vasoconstriction)
- P2X receptor ^[2]

Type	Gated by	Gene	Location	Function
IP₃ receptor	IP₃		ER/SR	Releases calcium from ER/SR in response to IP₃ by e.g. GPCRs ^[1]
Ryanodine receptor	dihydropyridine receptors in T-tubules		ER/SR	Calcium-induced calcium release in myocytes ^[1]
Two-pore channel
Cation channels of sperm
store-operated channels	indirectly by ER/SR depletion of calcium^[1]		plasma membrane

Pharmacology[edit | edit source]

Calcium channel blockers are used to treat hypertension.

References[edit | edit source]

↑ ^1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 ^1.6 ^1.7 Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4. Page 53
↑ Walter F., PhD. Boron. Medical Physiology: A Cellular And Molecular Approaoch. Elsevier/Saunders. ISBN 1-4160-2328-3. Page 479

External links[edit | edit source]

Calcium+Channels at the US National Library of Medicine Medical Subject Headings (MeSH)

de:Calciumkanal

Template:WikiDoc Sources

[Rang53-1] 1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 ^1.6 ^1.7 Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4. Page 53

[boron-2] Walter F., PhD. Boron. Medical Physiology: A Cellular And Molecular Approaoch. Elsevier/Saunders. ISBN 1-4160-2328-3. Page 479

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