antagonist

拮抗薬 　 　 　

WordNet

1. a drug that neutralizes or counteracts the effects of another drug
2. a muscle that relaxes while another contracts; "when bending the elbow the triceps are the antagonist"
3. incapable of harmonious association
4. characterized by antagonism or antipathy; "slaves antagonistic to their masters"; "antipathetic factions within the party" (同)antipathetic, antipathetical
5. indicating opposition or resistance (同)counter
6. used especially of drugs or muscles that counteract or neutralize each others effect (同)incompatible
7. arousing animosity or hostility; "his antagonistic brusqueness"; "Europe was antagonistic to the Unites States"
8. a class of drugs that inhibit (block) some biological process (同)blocking_agent
9. a football player whose responsibility is to block players attempting to stop an offensive play

PrepTutorEJDIC

1. 対立する人,敵対者,競争相手(opponent)
2. 敵対する,反目する;(…に)敵対している《+『to』+『名』》

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/12/21 21:23:05」(JST)

wiki ja

[Wiki ja表示]

アンタゴニスト (antagonist)とは生体内の受容体分子に働いて神経伝達物質やホルモンなど働きを阻害する薬のこと。

概要

拮抗薬（きっこうやく）、拮抗剤（—ざい）、拮抗物質（—ぶっしつ）、遮断薬（しゃだんやく）、ブロッカーとも呼ぶ。作用自体はないが受容体に可逆的に結合するため、濃度支配的に受容体が本来のリガンド分子と結合する部位を奪い合うことでアゴニストの作用を阻害する競合的拮抗薬（コンペティティブ・アンタゴニスト）と、受容体の結合定数に影響を及ぼしたり受容体と不可逆的に結合するなどしてアゴニストの作用を阻害する非競合的拮抗薬（ノンコンペティティブ・アンタゴニスト）がある。

アンタゴニスト存在下で、アゴニストによる濃度-作用曲線（ドーズ・レスポンスカーブ）を描かせると、競合的拮抗薬の場合では高濃度側へのカーブシフトが起こり、非競合的拮抗薬の場合は最大反応の低下が起こる。

リガンドの構造としてノルエピネフリンやドパミンなどのカテコールアミンを例に取ると、カテコール環の部位が作用発現に必要な作用基（ファンクショナル・モエティー）で、炭素鎖をもつアミンの部位が結合基（バインディング・モエティー）であると考えられる。 したがって、作用基であるカテコール環に改変を加えるとアンタゴニストとして働く場合が多い。 一方で、結合基に改変を加えると、受容体サブタイプへの選択性や作用濃度域の変化をもたらすことが多い。

有名なアンタゴニストの例

吹き矢毒クラーレの成分、D-ツボクラリンは、アンタゴニストとして有名な例であり、アセチルコリン受容体と呼ばれるタンパク質を選択的に阻害することで、神経や筋肉の活動を停止させる。

関連項目

• ミカエリス・メンテン式 - 競争阻害、非競争阻害について解説

wiki en

[Wiki en表示]

This article is about the literary term. For the pharmacological term, see receptor antagonist. For other uses, see Antagonist (disambiguation).

An antagonist (from Greek ἀνταγωνιστής - antagonistēs , "opponent, competitor, enemy, rival", from anti- "against" + agonizesthai "to contend for a prize,") is a character, group of characters, or institution that represents the opposition against which the protagonist or protagonists must contend. In other words, an antagonist is a person or a group of people who oppose the main character(s).

In the classic style of stories wherein the action consists of a hero fighting a villain/enemy, the two can be regarded as protagonist and antagonist, respectively. Of course, some narratives cast the villain the protagonist role, with the opposing hero as the antagonist.

The antagonist may also represent a major threat or obstacle to the main character by their very existence, without necessarily deliberately targeting him or her.

Examples in both film and theatre include Sauron, the main antagonist in The Lord of the Rings, who constantly battles the series' protagonists, and Tybalt, an antagonist in Romeo and Juliet, who slays Mercutio and whose later death results in the exiling of the play's protagonist, Romeo. A convention of the antagonist in a story is that their moral choices are less savoury than those of the protagonist. This is often used by an author to create conflict within a story. However, this is merely a convention and the reversal of this can be seen in the character Macduff from Macbeth, who is arguably morally correct in his desire to fight the tyrant Macbeth.

See also

• Archenemy
• Villain

References

UpToDate Contents

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English Journal

• Finding the right dose of fulvestrant in breast cancer.

• Estévez L, Alvarez I, Tusquets I, Seguí MA, Muñoz M, Fernández Y, Lluch A.SourceMedical Oncology Department, Centro Integral Oncológico Clara Campal, Madrid, Spain. Electronic address: lauraestevez@hospitaldemadrid.com.
• Cancer treatment reviews.Cancer Treat Rev.2013 Apr;39(2):136-41. doi: 10.1016/j.ctrv.2012.06.003. Epub 2012 Jul 15.
• Fulvestrant is a selective estrogen receptor downregulator, behaving as a complete antagonist. It was initially approved, at a dose of 250mg, to treat hormone dependant breast cancer in second line setting. However, a series of pharmacological and pre-clinical studies have suggested that a higher do
• PMID 22795960

• Introgression of Brown Norway CYP4A genes on to the Dahl salt-sensitive background restores vascular function in SS-5BN consomic rats.

• Lukaszewicz KM, Falck JR, Manthati VL, Lombard JH.Source*Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, U.S.A.
• Clinical science (London, England : 1979).Clin Sci (Lond).2013 Mar 1;124(5):333-42. doi: 10.1042/CS20120232.
• The present study tested the hypothesis that the Dahl SS (salt-sensitive) rat has vascular dysfunction due, in part, to the up-regulation of the CYP4A/20-HETE (cytochrome P450 ω-hydroxylase 4A)/20-hydroxyeicosatetraenoic acid) system. To assess the role of vascular 20-HETE, SS rats were compared wi
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• Memory in aged mice is rescued by enhanced expression of the GluN2B subunit of the NMDA receptor.

• Brim BL, Haskell R, Awedikian R, Ellinwood NM, Jin L, Kumar A, Foster TC, Magnusson KR.SourceMolecular and Cellular Biosciences Program, Oregon State University, Corvallis, OR 97331, USA; Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA; Healthy Aging Program, Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
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Japanese Journal

• Effects of neostigmine on bronchoconstriction with continuous electrical stimulation in rats.

• Ishii Koji,Shibata Osamu,Nishioka Kenji,Tsuda Atsushi,Makita Tetsuji,Sumikawa Koji
• Journal of Anesthesia 26(1), 80-84, 2012-02
• … In an in vitro study we examined whether tetrodotoxin (TTX), an Na(+)-channel blocker, 4-DAMP, a muscarinic M(3) receptor antagonist, or neostigmine could affect c-EFS-induced contraction of the tracheal ring. …
• NAID 120003850285

• Effect of the steroid receptor antagonist RU486 (mifepristone) on an IFNγ-induced persistent Chlamydophila pneumoniae infection model in epithelial HEp-2 cells

• Ishida Kasumi,Yamazaki Tomohiro,Motohashi Kazuki,Kobayashi Miho,Matsuo Junji,Osaki Takako,Hanawa Tomoko,Kamiya Shigeru,Yamamoto Yoshimasa,Yamaguchi Hiroyuki
• Journal of Infection and Chemotherapy 18(1), 22-29, 2012-02
• … We have previously demonstrated that the steroid receptor antagonist mifepristone (RU486) causes growth inhibition of Chlamydophila pneumoniae by binding to and subsequently destroying the bacteria during their normal developmental cycle in epithelial HEp-2 cells. …
• NAID 120003783328

• Structure of the human M2 muscarinic acetylcholine receptor bound to an antagonist

• Haga Kazuko,Kruse Andrew C.,Asada Hidetsugu,Yurugi-Kobayashi Takami,Shiroishi Mitsunori,Zhang Cheng,Weis William I.,Okada Tetsuji,Kobilka Brian K.,Haga Tatsuya,Kobayashi Takuya
• Nature, 2012-01-25
• … The antagonist 3-quinuclidinyl-benzilate binds in the middle of a long aqueous channel extending approximately two-thirds through the membrane.The orthosteric binding pocket is formed by amino acids that are identical in all five muscarinic receptor subtypes, and sharesstructural homology with other functionally unrelated acetylcholine binding proteins from different species. …
• NAID 120003752107

Related Links

• アンタゴニスト - Wikipedia

アンタゴニスト (antagonist)とは生体内の受容体分子に働いて神経伝達物質や ホルモンなど働きを阻害する薬のこと。 [編集] 概要. 拮抗薬（きっこうやく）、拮抗剤（— ざい）、拮抗物質（—ぶっしつ）、遮断薬（しゃだんやく）、ブロッカーとも呼ぶ。作用自体は ないが ...

• Antagonist&Agonist

Antagonist&Agonist 京都 「DRESSEDUNDRESSED」「ROGGYKEI」「Daniel Palillo 」「BLANK」「CILANDSIA」「Transvestite」「RehersalL」「m.soeur」「unruly」「banal chic bizarre」「HIRO」「KAMO」等取扱セレクトショップ。

Related Pictures

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★リンクテーブル★

リンク元	「アンタゴニスト」「アゴニスト」「blocker」「拮抗剤」「拮抗物質」
拡張検索	「antagonistic」「antagonist muscle」「irreversible antagonist」「metabolic antagonist」

「アンタゴニスト」

　　[★]

英

antagonist

同

拮抗薬、遮断薬、類似体拮抗物質 analog inhibitor

アゴニスト	作用薬	agonist	内因性の化学情報伝達物質と同じ受容体に結合し、同じ生理作用を呈する
アンタゴニスト	拮抗薬	antagonist	内因性の化学情報伝達物質と同じ受容体に結合するが、生理作用を呈しない
	部分作用薬	partial agonist	拮抗薬のうち、弱いながら生理作用を呈する
	部分拮抗薬	partial antagonist

「アゴニスト」

　　[★]

英

agonist

同

作用薬、作動薬

関

アゴニスト	作用薬	agonist	内因性の化学情報伝達物質と同じ受容体に結合し、同じ生理作用を呈する
アンタゴニスト	拮抗薬	antagonist	内因性の化学情報伝達物質と同じ受容体に結合するが、生理作用を呈しない
	部分作用薬	partial agonist	拮抗薬のうち、弱いながら生理作用を呈する
	部分拮抗薬	partial antagonist

-作動薬

-agonist

「blocker」

　　[★]

• n.

• 遮断薬、ブロッカー、遮断剤、阻害薬

関

antagonist、blocking agent、inhibitor

　 　

「拮抗剤」

　　[★]

英

antagonist

関

アンタゴニスト、拮抗筋、拮抗物質、拮抗薬、遮断薬

「拮抗物質」

　　[★]

英

antagonist

関

アンタゴニスト、拮抗筋、拮抗剤、拮抗薬、遮断薬

「antagonistic」

　　[★]

• 拮抗性の、拮抗的な、アンタゴニストの

関

antagonist、antagonistically、antagonizing

　 　 　 　 　 　

「antagonist muscle」

　　[★]

• 拮抗筋

関

antagonist、antagonistic muscle

「irreversible antagonist」

　　[★]

• 不可逆的遮断薬、非可逆的拮抗薬

「metabolic antagonist」

　　[★]

• 代謝拮抗物質

関

antimetabolite