WordNet

direct the flow of; "channel information towards a broad audience" (同)canalize, canalise
a television station and its programs; "a satellite TV channel"; "surfing through the channels"; "they offer more than one hundred channels" (同)television channel, TV channel
a passage for water (or other fluids) to flow through; "the fields were crossed with irrigation channels"; "gutters carried off the rainwater into a series of channels under the street"
(often plural) a means of communication or access; "it must go through official channels"; "lines of communication were set up between the two firms" (同)communication channel, line
a path over which electrical signals can pass; "a channel is typically what you rent from a telephone company" (同)transmission channel
a deep and relatively narrow body of water (as in a river or a harbor or a strait linking two larger bodies) that allows the best passage for vessels; "the ship went aground in the channel"
write by means of a keyboard with types; "type the acceptance letter, please" (同)typewrite
a small metal block bearing a raised character on one end; produces a printed character when inked and pressed on paper; "he dropped a case of type, so they made him pick them up"
(biology) the taxonomic group whose characteristics are used to define the next higher taxon
a subdivision of a particular kind of thing; "what type of sculpture do you prefer?"
all of the tokens of the same symbol; "the word `element contains five different types of character"
printed characters; "small type is hard to read"
identify as belonging to a certain type; "Such people can practically be typed" (同)typecast
a white metallic element that burns with a brilliant light; the fifth most abundant element in the earths crust; an important component of most plants and animals (同)Ca, atomic number 20
the 12th letter of the Roman alphabet (同)l
writing done with a typewriter (同)typewriting

PrepTutorEJDIC

〈C〉『水路』(川・湾・運河の船の通行ができる深い部分) / 〈U〉河床・川底 / 〈C〉『海峡』 / 〈C〉みぞ(groove),(道路の)水渠(すいきょ) / 《複数形で》(運搬・伝達の)正式の経路(手続き);(一般に)経路 / 〈C〉(テレビ・ラジオの)チャンネル / …‘に'水路を開く / …‘に'みぞを堀る / …'を'伝える,流す
〈C〉(…の)『型』,タイプ,類型,種類(kind)《+of+名》 / 〈C〉(その種類の特質を最もよく表している)『典型』,手本,模範《+of+名》 / 〈U〉《集合的に》活字;〈C〉(1個の)活字 / 〈U〉(印刷された)字体,活字 / 〈C〉(貨幣・メダルなどの)模様,図柄 / 〈C〉血液型(blood group) / …‘を'タイプに打つ / (…として)…‘を'分類する《+名+as+名(doing)》 / …‘の'型を決める / タイプライターを打つ
『カルシウム』(金属元素;化学記号は『Ca』)
lira(イタリアの貨幣単位リラ)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/06/16 19:16:30」(JST)

wiki en

Immunohistochemical analysis of L-type calcium channel Cav1.3 (CACNA1D) in human adrenal cortex. Marked immunoreactivity was detected in the zona glomerulosa. In the figure: ZG = zona glomerulosa, ZF = zona fasciculata, AC = adrenal capsule. Immunohistochemistry was performed according to published methods.^[1]

The L-type calcium channel (also known as the dihydropyridine channel, or DHP channel) is part of the high-voltage activated family of voltage-dependent calcium channel. "L" stands for long-lasting referring to the length of activation. This channel has four subunits (Cav1.1, Cav1.2, Cav1.3, Cav1.4).

L-type calcium channels are responsible for the excitation-contraction coupling of skeletal, smooth, cardiac muscle and for aldosterone secretion in endocrine cells of the adrenal cortex.^[1]

In cardiac myocytes, the L-type calcium channel passes inward Ca²⁺ current and triggers calcium release from the sarcoplasmic reticulum by activating ryanodine receptor 2 (RyR2) (calcium-induced-calcium-release).^[2] Phosphorylation of these channels increases their permeability to calcium and increases the contractility of their respective cardiac myocytes.

L-type calcium channel blocker drugs are used as cardiac antiarrhythmics or antihypertensives, depending on whether the drugs have higher affinity for the heart (the phenylalkylamines, like verapamil), or for the vessels (the dihydropyridines, like nifedipine).

In skeletal muscle, there is a very high concentration of L-type calcium channels, situated in the T-tubules. Muscle depolarization results in large gating currents, but anomalously low calcium flux, which is now explained by the very slow activation of the ionic currents. For this reason, little or no Ca²⁺ passes across the T-tubule membrane during a single action potential.

Structure

Like most voltage-gated ion channels, the α-subunit is composed of 4 subunits. Each subunit is formed by 6 alpha-helical, transmembrane domains that cross the membrane (numbered S1-S6). The S1-S4 subunits make up the voltage sensor, while S5-S6 subunits make up the selectivity filter.^[3]

Alpha subunit of a generic voltage-gated ion channel

Genes

CACNA1C, CACNA1D, CACNA1S, CACNA1F

References

^ ^a ^b Felizola SJ, Maekawa T, Nakamura Y, Satoh F, Ono Y, Kikuchi K, Aritomi S, Ikeda K, Yoshimura M, Tojo K, Sasano H (2014). "Voltage-gated calcium channels in the human adrenal and primary aldosteronism.". J Steroid Biochem Mol Biol. 144 (part B): 410–416. doi:10.1016/j.jsbmb.2014.08.012. PMID 25151951.
^ Yamakage M, Namiki A (2002). "Calcium channels — basic aspects of their structure, function and gene encoding; anesthetic action on the channels — a review". Can J Anaesth 49 (2): 151–64. doi:10.1007/BF03020488. PMID 11823393.
^ Catterall, William A.; Perez-Reyes, Edward; Snutch, Terrance P.; Striessnig, Joerg (December 2005). "International Union of Pharmacology. XLVIII. Nomenclature and Structure-Function Relationships of Voltage-Gated Calcium Channels". Pharmacol Rev 57 (4): 411–425. doi:10.1124/pr.57.4.5. PMID 16382099. Retrieved 30 November 2014.

External links

"Voltage-Gated Calcium Channels". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology.
L-Type Calcium Channel at the US National Library of Medicine Medical Subject Headings (MeSH)

UpToDate Contents

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English Journal

Contribution of Ion Channels in Calcium Signaling Regulating Phagocytosis: MaxiK, Cav1.3 and Bestrophin-1.

Strauß O1, Reichhart N2, Gomez NM3, Müller C4.
Advances in experimental medicine and biology.Adv Exp Med Biol.2016;854:739-44. doi: 10.1007/978-3-319-17121-0_98.
Mutations in the BEST1 gene lead to a variety of retinal degenerations including Best's vitelliforme macular degeneration. The BEST1 gene product, bestrophin-1, is expressed in the retinal pigment epithelium (RPE). It is likely that mutant bestrophin-1 impairs functions of the RPE which support phot
PMID 26427483

Cellular mechanisms of activity-dependent BDNF expression in primary sensory neurons.

Vermehren-Schmaedick A1, Khanjian RA1, Balkowiec A2.
Neuroscience.Neuroscience.2015 Dec 3;310:665-73. doi: 10.1016/j.neuroscience.2015.10.007. Epub 2015 Oct 10.
Brain-derived neurotrophic factor (BDNF) is abundantly expressed by both developing and adult rat visceral sensory neurons from the nodose ganglion (NG) in vivo and in vitro. We have previously shown that BDNF is released from neonatal NG neurons by activity and regulates dendritic development in th
PMID 26459016