ヒトにおけるプロテアゼ活性化受容体1型アゴニズムによる血管への直接的な効果 in vivo
Ingibjörg J Gudmundsdóttir1, Ian L Megson, Jillian S Kell
1Centre for Cardiovascular Science, University of Edinburgh, Royal Infirmary, 49 Little France Crescent, Edinburgh, EH16 4SB, UK. Ingibjorg.Gudmunds@ed.ac.uk
Circulation
|October 4, 2006
まとめ
人間におけるプロテアゼ活性化受容体1型 (PAR-1) の活性化により,血小板の活性化,静脈収縮,動脈の膨張が起こります. これらの発見は,PAR-1を明らかにしています.
科学分野:
- 心血管生理学 心血管の生理学
- トロンボシス研究研究
- 薬理学 薬理学とは
背景:
- プロテアゼ活性化受容体1型 (PAR-1) は,ヒトにおける重要なトロンビン受容体である.
- その in vivo 血管作用については,さらなる定義が必要である.
研究 の 目的:
- 人間におけるPAR-1アゴニズムの直接的な血管効果を調査する.
- ヒトの循環系におけるPAR-1の役割を明らかにする.
主な方法:
- PAR-1アゴニスト (SFLLRN) と PAR-2アゴニスト (SLIGKV) の局所静脈注入を,健康なボランティアに施した.
- 測定対象には,背手の静脈直径,前腕の血流量,血小板単細胞結合,および血マーカー (tPA,PAI-1,vWF) が含まれていた.
主要な成果:
- PAR-1アゴニズム (SFLLRN) 誘発による用量依存性静脈収縮と前腕の血流の増加,tPAの放出,および血小板単細胞結合.
- SFLLRNの静脈への影響は,ノレピネフリンやチロフィバンとは独立していた.
- PAR-2アゴニズム (SLIGKV) は,tPAの放出に影響を与えることなく,静脈と動脈の両方の膨張をもたらしました.
結論:
- PAR-1の活性化 in vivoは血小板活性化,静脈収縮,動脈膨張,tPAの放出を誘発する.
- これらの異なる血管反応は,トロンビンの生理学的および病理学的役割についての洞察を提供します.
関連する概念動画
Adrenergic Receptors: ɑ Subtype
2.8K
Adrenoceptors are classified into α and ꞵ classes based on their potencies to catecholamine agonists. α-adrenoceptors show the following order of catecholamine potency:
Adrenaline ≥ Noradrenaline >> Isoprenaline
α-adrenoceptors are further divided into α1 and α2-adrenoceptors.
α1-Adrenoceptors: These receptors are located postsynaptically on the effector organs and cause constriction of smooth muscle mediated by activation of phospholipase...
Adrenaline ≥ Noradrenaline >> Isoprenaline
α-adrenoceptors are further divided into α1 and α2-adrenoceptors.
α1-Adrenoceptors: These receptors are located postsynaptically on the effector organs and cause constriction of smooth muscle mediated by activation of phospholipase...
2.8K
Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors
2.7K
Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing...
2.7K
Antihypertensive Drugs: Angiotensin II Receptor Blockers
3.0K
In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth...
3.0K
Antihypertensive Drugs: Direct Renin Inhibitors
1.9K
The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,...
1.9K
Treatment for Pulmonary Arterial Hypertension: Endothelin Receptor Antagonists
619
Endothelins (ETs) are potent vasoactive peptides critical in the human body's various physiological and pathological processes. One of the most promising therapeutic strategies for treating pulmonary arterial hypertension (PAH) involves counteracting the effects of these endothelins using a class of drugs known as endothelin receptor antagonists.
ETs are synthesized through a complex sequence of enzymatic steps, primarily involving an enzyme referred to as endothelin-converting enzyme...
ETs are synthesized through a complex sequence of enzymatic steps, primarily involving an enzyme referred to as endothelin-converting enzyme...
619
Treatment for Pulmonary Arterial Hypertension: Prostacyclin Receptor Agonists
618
Prostacyclin receptor agonists are a class of therapeutic agents integral to managing pulmonary arterial hypertension (PAH). These drugs operate by mimicking the action of prostaglandin I2, or PGI2, a naturally occurring compound in the body.
These agonists bind to the IPR receptor situated on the plasma membrane of the pulmonary artery smooth muscle cells. This binding triggers a cascade of reactions known as the GS-AC-cAMP-PKA pathway. This pathway results in the relaxation of smooth muscle...
These agonists bind to the IPR receptor situated on the plasma membrane of the pulmonary artery smooth muscle cells. This binding triggers a cascade of reactions known as the GS-AC-cAMP-PKA pathway. This pathway results in the relaxation of smooth muscle...
618


