Calcium channel Information & Calcium channel Links at HealthHaven.com

A Calcium channel is an ion channel which displays selective permeabiltiy to calcium ions. It is sometimes synonymous as voltage-dependent calcium channel,^[1] although there are also ligand-gated calcium channels.^[2]

[edit] Comparison tables

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

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 ^[3]. 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 ^[3]
N-type	high voltage	Ca_v2.2	CACNA1B	Throughout the brain	neurotransmitter release ^[3]
R-type	intermediate voltage	Ca_v2.3	CACNA1E	Cerebellar granule cells, other neurons	?^[3]
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^[3]

the receptor-operated calcium channels (in vasoconstriction)
- P2X receptor ^[4]

Type	Gated by	Gene	Location	Function
IP₃ receptor	IP₃		ER/SR	Releases calcium from ER/SR in response to IP₃ by e.g. GPCRs ^[3]
Ryanodine receptor	dihydropyridine receptors in T-tubules and increased intracellular calcium (Calcium Induced Calcium Release - CICR)		ER/SR	Calcium-induced calcium release in myocytes ^[3]
Two-pore channel
Cation channels of sperm
store-operated channels	indirectly by ER/SR depletion of calcium^[3]		plasma membrane

^ calcium channel at Dorland's Medical Dictionary
^ Striggow F, Ehrlich BE (August 1996). "Ligand-gated calcium channels inside and out". Curr. Opin. Cell Biol. 8 (4): 490–5. doi:10.1016/S0955-0674(96)80025-1. PMID 8791458. http://linkinghub.elsevier.com/retrieve/pii/S0955-0674(96)80025-1.
^ ^a ^b ^c ^d ^e ^f ^g ^h Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4. Page 53
^ Walter F., PhD. Boron (2005). Medical Physiology: A Cellular And Molecular Approach. Elsevier/Saunders. ISBN 1-4160-2328-3. Page 479

"Voltage-Gated Ion Channels". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. http://www.iuphar-db.org/IC/ReceptorFamiliesForward.
MeSH Calcium+Channels