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"
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
official routes of communication; "you have to go through channels"

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
『カルシウム』(金属元素;化学記号は『Ca』)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/11/27 06:00:19」(JST)

wiki en

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

Comparison tables

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

Voltage-gated

Type	Voltage	α₁ subunit (gene name)	Associated subunits	Most often found in
L-type calcium channel ("Long-Lasting" AKA "DHP Receptor")	HVA (high voltage activated)	Ca_v1.1 (CACNA1S) Ca_v1.2 (CACNA1C) Ca_v1.3 (CACNA1D) Ca_v1.4 (CACNA1F)	α₂δ, β, γ	Skeletal muscle, smooth muscle, bone (osteoblasts), ventricular myocytes** (responsible for prolonged action potential in cardiac cell; also termed DHP receptors), dendrites and dendritic spines of cortical neurons
P-type calcium channel ("Purkinje") /Q-type calcium channel	HVA (high voltage activated)	Ca_v2.1 (CACNA1A)	α₂δ, β, possibly γ	Purkinje neurons in the cerebellum / Cerebellar granule cells
N-type calcium channel ("Neural"/"Non-L")	HVA (high-voltage-activated)	Ca_v2.2 (CACNA1B)	α₂δ/β₁, β₃, β₄, possibly γ	Throughout the brain and peripheral nervous system.
R-type calcium channel ("Residual")	intermediate-voltage-activated	Ca_v2.3 (CACNA1E)	α₂δ, β, possibly γ	Cerebellar granule cells, other neurons
T-type calcium channel ("Transient")	low-voltage-activated	Ca_v3.1 (CACNA1G) Ca_v3.2 (CACNA1H) Ca_v3.3 (CACNA1I)		neurons, cells that have pacemaker activity, bone (osteocytes), thalamus (thalamus)

Ligand-gated

the receptor-operated calcium channels (in vasoconstriction)
- P2X receptors^[3]

Type	Gated by	Gene	Location	Function
IP₃ receptor	IP₃	ITPR1, ITPR2, ITPR3	ER/SR	Releases calcium from ER/SR in response to IP₃ by e.g. GPCRs^[4]
Ryanodine receptor	dihydropyridine receptors in T-tubules and increased intracellular calcium (Calcium Induced Calcium Release - CICR)	RYR1, RYR2, RYR3	ER/SR	Calcium-induced calcium release in myocytes^[4]
Two-pore channel
Cation channels of sperm
store-operated channels	indirectly by ER/SR depletion of calcium^[4]	ORAI1, ORAI2, ORAI3	plasma membrane

Pharmacology

L-type calcium channel blockers are used to treat hypertension. T-type calcium channel blockers are used to treat epilepsy.

References

^ "calcium channel" at Dorland's Medical Dictionary
^ Striggow F, Ehrlich BE (August 1996). "Ligand-gated calcium channels inside and out". Current Opinion in Cell Biology. 8 (4): 490–5. doi:10.1016/S0955-0674(96)80025-1. PMID 8791458.
^ Walter F., PhD. Boron (2005). Medical Physiology: A Cellular And Molecular Approach. Elsevier/Saunders. ISBN 1-4160-2328-3. Page 479
^ ^a ^b ^c Rang HP (2003). Pharmacology. Edinburgh: Churchill Livingstone. p. 54. ISBN 978-0-443-07145-4.

External links

"Voltage-Gated Ion Channels". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology.
"TRIP Database". a manually curated database of protein-protein interactions for mammalian TRP channels.
Calcium Channels at the US National Library of Medicine Medical Subject Headings (MeSH)

UpToDate Contents

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1. カルシウム拮抗剤の主な副作用および安全性 major side effects and safety of calcium channel blockers
2. カルシウム拮抗剤中毒 calcium channel blocker poisoning
3. 安定狭心症のマネージメントにおけるカルシウム拮抗剤 calcium channel blockers in the management of stable angina pectoris
4. Choice of drug therapy in primary (essential) hypertension
5. 重症筋無力症患者に対する麻酔 anesthesia for the patient with myasthenia gravis

English Journal

CRAC channel inhibition produces greater anti-inflammatory effects than glucocorticoids in CD8 cells from COPD patients.

Grundy S, Kaur M, Plumb J, Reynolds S, Hall S, House D, Begg M, Ray D, Singh D.Author information *University of Manchester NIHR Translational Research Facility, Manchester Academic Health Science Centre, University Hospital of South Manchester Foundation Trust, Manchester M23 9LT, U.K.AbstractThere are increased numbers of pulmonary CD8 lymphocytes in COPD (chronic obstructive pulmonary disease). CRAC (calcium release-activation calcium) channels play a central role in lymphocyte activation though the regulation of the transcription factor NFAT (nuclear factor of activated T-cells). We studied the expression of NFAT in lungs from COPD patients compared with controls, and evaluated the effects of CRAC channel inhibition compared with corticosteroids on NFAT activation and cytokine production in CD8 cells from COPD patients. The effects of the corticosteroid dexamethasone, the calcineurin inhibitor cyclosporin and the CRAC channel inhibitor Synta 66 were studied on cytokine production and NFAT activation using peripheral blood and isolated pulmonary CD8 cells. NFAT1 and CD8 co-expression in the lungs was compared in COPD patients and controls using combined immunohistochemistry and immunofluorescence. NFAT inhibition with either cyclosporin or Synta 66 resulted in significantly greater maximal inhibition of cytokines than dexamethasone in both peripheral blood and pulmonary CD8 cells [e.g. >95% inhibition of IFNγ (interferon γ) production from pulmonary CD8 cells using cyclosporin and Synta 66 compared with <50% using dexamethasone]. The absolute number of pulmonary CD8 cells co-expressing NFAT1 was significantly raised in lungs from COPD patients compared with controls, but the percentage of CD8 cells co-expressing NFAT1 was similar between COPD patients and controls (80.7% compared with 78.5% respectively, P=0.3). Inhibition of NFAT using the CRAC channel Synta 66 produces greater anti-inflammatory effects on CD8 cells from COPD patients than corticosteroids. NFAT is expressed at a high level in pulmonary CD8 cells in COPD.
Clinical science (London, England : 1979).Clin Sci (Lond).2014 Feb;126(3):223-32. doi: 10.1042/CS20130152.
There are increased numbers of pulmonary CD8 lymphocytes in COPD (chronic obstructive pulmonary disease). CRAC (calcium release-activation calcium) channels play a central role in lymphocyte activation though the regulation of the transcription factor NFAT (nuclear factor of activated T-cells). We s
PMID 23905758

BKCa and hEag1 channels regulate cell proliferation and differentiation in human bone marrow-derived mesenchymal stem cells.

Zhang YY, Yue J, Che H, Sun HY, Tse HF, Li GR.Author information Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China.AbstractHuman bone marrow-derived mesenchymal stem cells (MSCs) serve as a reservoir for the continuous renewal of various mesenchymal tissues; however, cellular physiology of ion channels is not fully understood. The present study investigated potential roles of large-conductance Ca(2+) -activated potassium (BKCa ) channels and ether-à-go-go potassium (hEag1 or Kv10.1) channels in regulating cell proliferation and differentiation in human MSCs. We found that inhibition of BKCa with paxilline or hEag1 with astemizole, or knockdown of BKCa with shRNAs targeting KCa1.1 or hEag1 channels with shRNAs targeting KCNH1 arrested the cells at G0/G1 phase. In addition, silencing BKCa or hEag1 channels significantly reduced adipogenic differentiation with decrease of lipid accumulation and expression of the adipocyte marker PPARγ, and decreased osteogenic differentiation with reduction of mineral precipitation and osteocalcin. These effects were accompanied with a reduced cyclin D1, cyclin E, p-ERK1/2, and p-Akt. Our results demonstrate that BKCa and hEag1 channels not only regulate cell proliferation, but also participate in the adipogenic and osteogenic differentiations in human MSCs, which indicates that BKCa and hEag1 channels may be essential in maintaining bone marrow physiological function and bone regeneration.
Journal of cellular physiology.J Cell Physiol.2014 Feb;229(2):202-12. doi: 10.1002/jcp.24435.
Human bone marrow-derived mesenchymal stem cells (MSCs) serve as a reservoir for the continuous renewal of various mesenchymal tissues; however, cellular physiology of ion channels is not fully understood. The present study investigated potential roles of large-conductance Ca(2+) -activated potassiu
PMID 23881642

TMEM16E (GDD1) exhibits protein instability and distinct characteristics in chloride channel/pore forming ability.

Tran TT, Tobiume K, Hirono C, Fujimoto S, Mizuta K, Kubozono K, Inoue H, Itakura M, Sugita M, Kamata N.Author information Department of Oral and Maxillofacial Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.AbstractTMEM16E/GDD1 has been shown to be responsible for the bone-related late-onset disease gnathodiaphyseal dysplasia (GDD), with the dominant allele (TMEM16E(gdd) ) encoding a missense mutation at Cys356. Additionally, several recessive loss-of-function alleles of TMEM16E also cause late-onset limb girdle muscular dystrophy. In this study, we found that TMEM16E was rapidly degraded via the proteasome pathway, which was rescued by inhibition of the PI3K pathway and by the chemical chaperone, sodium butyrate. Moreover, TMEM16E(gdd) exhibited lower stability than TMEM16E, but showed similar propensity to be rescued. TMEM16E did not exhibit cell surface calcium-dependent chloride channel (CaCC) activity, which was originally identified in TMEM16A and TMEM16B, due to their intracellular vesicle distribution. A putative pore-forming domain of TMEM16E, which shared 39.8% similarity in 98 amino acids with TMEM16A, disrupted CaCC activity of TMEM16A via domain swapping. However, the Thr611Cys mutation in the swapped domain, which mimicked conserved cysteine residues between TMEM16A and TMEM16B, reconstituted CaCC activity. In addition, the GDD-causing cysteine mutation made in TMEM16A drastically altered CaCC activity. Based on these findings, TMEM16E possesses distinct function other than CaCC and another protein-stabilizing machinery toward the TMEM16E and TMEM16E(gdd) proteins should be considered for the on-set regulation of their phenotypes in tissues.
Journal of cellular physiology.J Cell Physiol.2014 Feb;229(2):181-90. doi: 10.1002/jcp.24431.
TMEM16E/GDD1 has been shown to be responsible for the bone-related late-onset disease gnathodiaphyseal dysplasia (GDD), with the dominant allele (TMEM16E(gdd) ) encoding a missense mutation at Cys356. Additionally, several recessive loss-of-function alleles of TMEM16E also cause late-onset limb gird
PMID 23843187

「カルシウム」

　　[★]

英: calcium
関: カルシウムイオン、リン; calcium channel blockers, calcium channels

基準値

血清総Ca 8.6-10.1 mg/dl(臨床検査法提要第32版)
8.6-10.2 mg/dL (QB)　　　だいたい　　9.4 ± 0.8
血清Caイオン 1.15-1.30 mmmol/l(臨床検査法提要第32版), 4.6-5.1 mg/dl

血液ガス

血液ガスでは (mEq/l)で出されるが 4倍すれば (mg/dl)に変換できる　　原子量が約40ゆえ

溶解度積

http://taniwa.hp.infoseek.co.jp/gyunyu/no9.html

リン酸カルシウム	366x10^-6	（30℃）
リン酸カルシウム	0.35x10^-6	（38℃）
炭酸カルシウム	0.0087x10^-6	（25℃）
酒石酸カルシウム	0.0077x10^-6	（25℃）
シュウ酸カルシウム	0.00257x10^-6	（25℃）
オレイン酸カルシウム	0.000291x10^-6	（25℃）
パルチミン酸カルシウム	0.000000161x10^-6	（23℃）