Endothelin: Difference between revisions

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== Endothelin ==
{{Short description|Peptides involved in vasoconstriction}}
{{DISPLAYTITLE:Endothelin}}


[[File:1EDN_human_endothelin1_02.png|Structure of human endothelin-1|thumb|right]]
[[File:1EDN_human_endothelin1_02.png|thumb|right|Structure of human endothelin-1]]


'''Endothelin''' is a family of peptides that play a crucial role in the regulation of vascular tone and blood pressure. These peptides are among the most potent vasoconstrictors known and are involved in various physiological and pathological processes.
'''Endothelins''' are a group of peptides with potent [[vasoconstrictor]] properties, playing a crucial role in the regulation of [[vascular tone]] and [[blood pressure]]. They are primarily produced by [[endothelial cells]] and have significant effects on various [[organ systems]].


== Structure ==
==Structure and Isoforms==
Endothelins are small peptides consisting of 21 amino acids. The family includes three isoforms: endothelin-1 (ET-1), endothelin-2 (ET-2), and endothelin-3 (ET-3). Each isoform is encoded by a separate gene and has distinct tissue distribution and function. The structure of endothelins is characterized by two disulfide bridges that form a unique "hairpin" shape, which is essential for their biological activity.
Endothelins are small [[peptides]] consisting of 21 [[amino acids]]. There are three isoforms of endothelin: [[endothelin-1]] (ET-1), [[endothelin-2]] (ET-2), and [[endothelin-3]] (ET-3). Each isoform is encoded by a separate gene and has distinct tissue distribution and physiological roles.


== Function ==
===Endothelin-1===
Endothelins primarily function as vasoconstrictors, meaning they cause blood vessels to constrict, leading to an increase in blood pressure. They exert their effects by binding to [[endothelin receptors]], which are G-protein-coupled receptors located on the surface of vascular smooth muscle cells. There are two main types of endothelin receptors: ETA and ETB. The binding of endothelins to these receptors triggers a cascade of intracellular events that result in muscle contraction and vasoconstriction.
ET-1 is the most studied and is primarily involved in the regulation of [[vascular tone]]. It is produced by endothelial cells and acts in a paracrine manner to induce vasoconstriction. ET-1 is also involved in [[cell proliferation]], [[inflammation]], and [[fibrosis]].


=== Endothelin-1 ===
===Endothelin-2 and Endothelin-3===
Endothelin-1 (ET-1) is the most studied and potent member of the endothelin family. It is primarily produced by endothelial cells, the cells lining the interior surface of blood vessels. ET-1 plays a significant role in maintaining vascular homeostasis and is involved in the pathogenesis of various cardiovascular diseases, including hypertension, heart failure, and atherosclerosis.
ET-2 and ET-3 have similar structures to ET-1 but differ in their tissue distribution and function. ET-2 is found in the [[kidneys]] and [[intestines]], while ET-3 is primarily located in the [[central nervous system]] and [[gastrointestinal tract]].


=== Endothelin-2 and Endothelin-3 ===
==Receptors==
Endothelin-2 (ET-2) and endothelin-3 (ET-3) have similar structures to ET-1 but differ in their tissue distribution and physiological roles. ET-2 is less well understood but is thought to have similar vasoconstrictive properties. ET-3 is primarily found in the gastrointestinal tract and the central nervous system, where it may play a role in neural signaling and gastrointestinal motility.
Endothelins exert their effects through binding to specific [[G protein-coupled receptors]]: [[endothelin receptor type A]] (ETA) and [[endothelin receptor type B]] (ETB). ETA receptors are primarily located on [[vascular smooth muscle cells]] and mediate vasoconstriction. ETB receptors are found on endothelial cells and can mediate both vasodilation and vasoconstriction, depending on the context.


== Pathophysiology ==
==Physiological Roles==
The dysregulation of endothelin production or receptor activity can lead to various pathological conditions. Overproduction of ET-1 is associated with [[hypertension]], [[pulmonary arterial hypertension]], and [[chronic kidney disease]]. In these conditions, the excessive vasoconstriction and vascular remodeling contribute to disease progression.
Endothelins are involved in various physiological processes, including:


== Therapeutic Implications ==
* '''Regulation of Vascular Tone:''' Endothelins are key regulators of blood vessel constriction and dilation, influencing blood pressure and flow.
Given the role of endothelins in disease, they are targets for therapeutic intervention. Endothelin receptor antagonists, such as bosentan and ambrisentan, are used in the treatment of pulmonary arterial hypertension. These drugs block the effects of endothelins, leading to vasodilation and reduced blood pressure.
* '''Cardiac Function:''' They play a role in [[cardiac contractility]] and [[heart rate]] regulation.
* '''Renal Function:''' Endothelins affect [[glomerular filtration rate]] and [[sodium]] excretion, impacting [[fluid balance]].
* '''Neural Activity:''' In the [[central nervous system]], endothelins modulate [[neurotransmitter]] release and [[neuronal]] excitability.


== Related pages ==
==Pathophysiology==
Dysregulation of endothelin production or receptor activity is implicated in several [[diseases]]:
 
* '''Hypertension:''' Overproduction of ET-1 can lead to sustained vasoconstriction and elevated blood pressure.
* '''Heart Failure:''' Endothelins contribute to [[cardiac remodeling]] and [[myocardial]] dysfunction.
* '''Pulmonary Arterial Hypertension (PAH):''' Increased endothelin activity is a hallmark of PAH, leading to elevated pulmonary vascular resistance.
* '''Renal Disease:''' Endothelins are involved in the progression of [[chronic kidney disease]] and [[glomerulonephritis]].
 
==Therapeutic Implications==
Endothelin receptor antagonists, such as [[bosentan]] and [[ambrisentan]], are used in the treatment of conditions like pulmonary arterial hypertension. These drugs block the effects of endothelins, reducing vasoconstriction and improving blood flow.
 
==Related Pages==
* [[Vasoconstriction]]
* [[Vasoconstriction]]
* [[Hypertension]]
* [[Endothelial cell]]
* [[Pulmonary arterial hypertension]]
* [[Pulmonary arterial hypertension]]
* [[Endothelial cell]]
* [[G protein-coupled receptor]]
* [[G-protein-coupled receptor]]


[[Category:Peptides]]
[[Category:Peptides]]
[[Category:Vasoconstrictors]]
[[Category:Cardiovascular physiology]]
[[Category:Cardiovascular physiology]]

Latest revision as of 17:17, 5 March 2025

Peptides involved in vasoconstriction



Structure of human endothelin-1

Endothelins are a group of peptides with potent vasoconstrictor properties, playing a crucial role in the regulation of vascular tone and blood pressure. They are primarily produced by endothelial cells and have significant effects on various organ systems.

Structure and Isoforms[edit]

Endothelins are small peptides consisting of 21 amino acids. There are three isoforms of endothelin: endothelin-1 (ET-1), endothelin-2 (ET-2), and endothelin-3 (ET-3). Each isoform is encoded by a separate gene and has distinct tissue distribution and physiological roles.

Endothelin-1[edit]

ET-1 is the most studied and is primarily involved in the regulation of vascular tone. It is produced by endothelial cells and acts in a paracrine manner to induce vasoconstriction. ET-1 is also involved in cell proliferation, inflammation, and fibrosis.

Endothelin-2 and Endothelin-3[edit]

ET-2 and ET-3 have similar structures to ET-1 but differ in their tissue distribution and function. ET-2 is found in the kidneys and intestines, while ET-3 is primarily located in the central nervous system and gastrointestinal tract.

Receptors[edit]

Endothelins exert their effects through binding to specific G protein-coupled receptors: endothelin receptor type A (ETA) and endothelin receptor type B (ETB). ETA receptors are primarily located on vascular smooth muscle cells and mediate vasoconstriction. ETB receptors are found on endothelial cells and can mediate both vasodilation and vasoconstriction, depending on the context.

Physiological Roles[edit]

Endothelins are involved in various physiological processes, including:

Pathophysiology[edit]

Dysregulation of endothelin production or receptor activity is implicated in several diseases:

  • Hypertension: Overproduction of ET-1 can lead to sustained vasoconstriction and elevated blood pressure.
  • Heart Failure: Endothelins contribute to cardiac remodeling and myocardial dysfunction.
  • Pulmonary Arterial Hypertension (PAH): Increased endothelin activity is a hallmark of PAH, leading to elevated pulmonary vascular resistance.
  • Renal Disease: Endothelins are involved in the progression of chronic kidney disease and glomerulonephritis.

Therapeutic Implications[edit]

Endothelin receptor antagonists, such as bosentan and ambrisentan, are used in the treatment of conditions like pulmonary arterial hypertension. These drugs block the effects of endothelins, reducing vasoconstriction and improving blood flow.

Related Pages[edit]