Space-filling models of angiotensin I (left) and II (right). From PDB 1N9U and 1N9V.
Angiotensinogen
Identifiers
Symbol	AGT
HUGO	333
Entrez	183
OMIM	106150
RefSeq	NM_000029
UniProt	P01019
Other data
Locus	Chr. 1 q41-qter

Angiotensin is an oligopeptide in the blood that causes vasoconstriction, increased blood pressure, and release of aldosterone from the adrenal cortex. It is a powerful dipsogen. It is derived from the precursor molecule angiotensinogen, a serum globulin produced in the liver. It plays an important role in the renin-angiotensin system. Image File history File links Size of this preview: 800 × 527 pixel Image in higher resolution (1413 × 931 pixel, file size: 351 KB, MIME type: image/png) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Angiotensin ... This is a calotte model of cyclohexane. ... The Protein Data Bank (PDB) is a repository for 3-D structural data of proteins and nucleic acids. ... Hugo is a masculine name. ... The Entrez logo The Entrez Global Query Cross-Database Search System allows access to databases at the National Center for Biotechnology Information (NCBI) website. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The National Center for Biotechnology Information (NCBI) is part of the US National Library of Medicine (NLM), which is a branch of the US National Institutes of Health. ... Swiss-Prot is a curated biological database of protein sequences created in 1986 by Amos Bairoch during his PhD and developed by the Swiss Institute of Bioinformatics and the European Bioinformatics Institute. ... Short and long arms Chromosome. ... Chromosome 1 is, by convention, the designation for the largest human chromosome. ... Peptides (from the Greek πεπτος, digestible), are the family of short molecules formed from the linking, in a defined order, of various α-amino acids. ... Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... The blood vessels are part of the circulatory system and function to transport blood throughout the body. ... A sphygmomanometer, a device used for measuring blood pressure. ... Aldosterone is a steroid hormone synthesized from cholesterol by the enzyme aldosterone synthase. ... Layers of cortex. ... A dipsogen is an agent that causes thirst. ... The liver is an organ in some animals, including vertebrates (and therefore humans). ... Schematic depicting how the RAAS works. ...

Precursor, and types of angiotensin

Angiotensinogen

Angiotensinogen is an α-2-globulin that is produced constitutively and released into the circulation mainly by the liver, although other sites are thought to be involved also. It is a member of the serpin family, although it is not known to inhibit other enzymes, unlike most serpins. Plasma angiotensinogen levels are increased by plasma corticosteroid, estrogen, thyroid hormone, and angiotensin II levels. Serpins (short for serine protease inhibitor) are a group of structurally related proteins, many of which inhibit peptidases (enzymes that degrade protein, old name: proteases). ... In physiology, corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. ... Estriol. ... Norepinephrine A hormone (from Greek όρμή - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ...

Angiotensinogen consist of 453 amino acid residues. Phenylalanine is one of the standard amino acids. ...

Angiotensin I

Renin-angiotensin-aldosterone system

 Asp-Arg-Val-Tyr-Ile-His-Pro-Phe-His-Leu 

Angiotensin I (CAS# 11128-99-7) is formed by the action of renin on angiotensinogen. Renin is produced in the kidneys in response to both decreased intra-renal blood pressure at the juxtaglomerular cells, or decreased delivery of Na+ and Cl- to the macula densa. If more Na+ is sensed, renin release is decreased. Image File history File links Download high resolution version (1050x585, 121 KB) Summary Description: The renin-angiotensin system (RAS) or the renin-angiotensin-aldosterone system (RAAS). ... Image File history File links Download high resolution version (1050x585, 121 KB) Summary Description: The renin-angiotensin system (RAS) or the renin-angiotensin-aldosterone system (RAAS). ... The renin-angiotensin system (RAS) or the renin-angiotensin-aldosterone system is a hormone system that helps regulate long-term blood pressure and blood volume in the body. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... Renin, also known as angiotensinogenase, is a circulating enzyme (EC 3. ... Angiotensinogen, angiotensin I and angiotensin II are peptides involved in maintenance of blood volume and pressure. ... It has been suggested that Renal anomalies and Renal plasma threshold be merged into this article or section. ... The juxtaglomerular cells are specialized cells that stimulate the secretion of the adrenal hormone aldosterone and play a major role in renal autoregulation, the kidneys self-governance. ... In the kidney, the macula densa is an area of closely packed specialized cells lining the distal convoluted tubule where it lies next to the glomerular vascular pole. ...

Renin cleaves the peptide bond between the leucine (Leu) and valine (Val) residues on angiotensinogen, creating the ten amino acid peptide (des-Asp) angiotensin I (CAS# 9041-90-1). A peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O). ... Leucine is one of the 20 most common amino acids and coded for by DNA. It is isomeric with isoleucine. ... Valine is one of the 20 natural amino acids, and is coded for in DNA. Nutritionally, valine is also an essential amino acid. ... Phenylalanine is one of the standard amino acids. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ...

Angiotensin I appears to have no biological activity and exists solely as a precursor to angiotensin II.

Angiotensin II

 Asp-Arg-Val-Tyr-Ile-His-Pro-Phe | His-Leu 

Angiotensin I is converted to angiotensin II through removal of two terminal residues by the enzyme Angiotensin-converting enzyme (ACE, or kininase), which is found predominantly in the capillaries of the lung.^[1] Angiotensin converting enzyme Angiotensin-Converting Enzyme (ACE, EC 3. ... This article or section does not adequately cite its references or sources. ...

ACE is a target for inactivation by ACE inhibitor drugs, which decrease the rate of angiotensin II production. Other cleavage products, 7 or 9 amino acids long, are also known; they have differential affinity for angiotensin receptors, although their exact role is still unclear. The action of angiotensin II itself is targeted by angiotensin II receptor antagonists, which directly block angiotensin II AT₁ receptors. Captopril, the first ACE inhibitor ACE inhibitors, or inhibitors of Angiotensin-Converting Enzyme, are a group of pharmaceuticals that are used primarily in treatment of hypertension and congestive heart failure, in most cases as the drugs of first choice. ... The angiotensin receptors are a class of G protein-coupled receptors with angiotensins as ligands. ... Angiotensin II receptor antagonists, also known as angiotensin receptor blockers (ARBs) or AT1-receptor antagonists, are a group of pharmaceuticals which modulate the renin-angiotensin-aldosterone system. ... The angiotensin receptors are a class of G protein-coupled receptors with angiotensins as ligands. ...

Angiotensin II is degraded to angiotensin III by angiotensinases that are located in red blood cells and the vascular beds of most tissues. It has a half-life in circulation of around 30 seconds, while in tissue, it may be as long as 15-30 minutes.

Angiotensin III

 Asp | Arg-Val-Tyr-Ile-His-Pro-Phe 

Angiotensin III has 40% of the pressor activity of Angiotensin II, but 100% of the aldosterone-producing activity. Vasoconstriction is the constriction of blood vessels, in other words, when the lumen narrows. ...

Angiotensin IV

 Arg | Val-Tyr-Ile-His-Pro-Phe 

Angiotensin IV is a hexapeptide which, like angiotensin III, has some lesser activity.

Effects of angiotensin

See also Renin-angiotensin_system#Effects

Angiotensins II, III & IV have a number of effects throughout the body: Schematic depicting how the RAAS works. ...

Cardiovascular effects

It is a potent direct vasoconstrictor, constricting arteries and veins and increasing blood pressure. Vasoconstriction is the constriction of blood vessels, in other words, when the lumen narrows. ...

Angiotensin II has prothrombotic potential through adhesion and aggregation of platelets and production of PAI-1 and PAI-2. A 250 ml bag of newly collected platelets. ... Plasminogen activator inhibitor-1 is the principal inhibitor of tissue plasminogen activator (tPA) and urokinase (uPA), the activators of plasminogen and hence fibrinolysis (the physiological breakdown of blood clots). ... Plasminogen activator inhibitor-2 (placental PAI) is a coagulation factor which inactivates tPA & urokinase. ...

It has been proposed that angiotensin II could be a cause of vascular and cardiac muscle hypertrophy (enlargement of the heart). Cardiac muscle is a type of involuntary mononucleated, or uninucleated, striated muscle found exclusively within the heart. ... Bodybuilder Markus Rühl has marked hypertrophy of skeletal muscle. ... The heart and lungs, from an older edition of Grays Anatomy. ...

Neural effects

Angiotensin II increases thirst sensation (dipsogen) through the subfornical organ (SFO) of the brain, decreases the response of the baroreceptor reflex, and increases the desire for salt. It increases secretion of ADH in the posterior pituitary and secretion of ACTH in the anterior pituitary. It also potentiates the release of norepinephrine by direct action on postganglionic sympathetic fibers. William-Adolphe Bouguereaus Thirst (1886) Thirst is the basic need or instinct of humans or animals to drink. ... A dipsogen is an agent that causes thirst. ... The Subfornical organ is one of the circumventricular organs of the brain and is involved in thirst-regulation. ... Baroreflex, also called baroreceptor reflex is the system in the body that regulates blood pressure. ... Edible salt is a mineral, one of the few rocks people eat. ... Arginine vasopressin (AVP), also known as argipressin or antidiuretic hormone (ADH), is a human hormone that is mainly released when the body is low on water; it causes the kidneys to conserve water by concentrating the urine and reducing urine volume. ... The posterior pituitary (also called the neurohypophysis) comprises the posterior lobe of the pituitary gland and is part of the endocrine system. ... Adrenocorticotropic hormone (ACTH or corticotropin) is a polypeptide hormone secreted from corticotropes in the anterior lobe of the pituitary gland in response to corticotropin-releasing hormone (CRH) released by the hypothalamus. ... Norepinephrine (INN) or noradrenaline (BAN) is a catecholamine and a phenethylamine with chemical formula C8H11NO3. ... Grays FIG. 838– The right sympathetic chain and its connections with the thoracic, abdominal, and pelvic plexuses. ...

Adrenal effects

Angiotensin II acts on the adrenal cortex, causing it to release aldosterone, a hormone that causes the kidneys to retain sodium and lose potassium. Elevated plasma angiotensin II levels are responsible for the elevated aldosterone levels present during the luteal phase of the menstrual cycle. Layers of cortex. ... Aldosterone is a steroid hormone synthesized from cholesterol by the enzyme aldosterone synthase. ... Menstrual cycle The menstrual cycle is a recurring cycle of physiological changes in the females of some animal species that is associated with reproductive fertility. ...

Renal effects

Angiotensin II has a direct effect on the proximal tubules to increase Na⁺ resorption. Although it slightly inhibits glomerular filtration by indirectly (through sympathetic effects) and directly stimulating mesangial cell constriction, its overall effect is to increase the glomerular filtration rate by increasing the renal perfusion pressure via efferent renal arteriole constriction. Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal glomerular capillaries into the Bowmans capsule per unit time. ... Mesangial cells are specialized cells around blood vessels in the kidneys. ... Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal glomerular capillaries into Bowmans capsule per unit time. ...

See also

• ACE inhibitor
• Angiotensin receptor
• Angiotensin II receptor antagonist

Captopril, the first ACE inhibitor ACE inhibitors, or inhibitors of Angiotensin-Converting Enzyme, are a group of pharmaceuticals that are used primarily in treatment of hypertension and congestive heart failure, in most cases as the drugs of first choice. ... The angiotensin receptors are a class of G protein-coupled receptors with angiotensins as ligands. ... Angiotensin II receptor antagonists, also known as angiotensin receptor blockers (ARBs) or AT1-receptor antagonists, are a group of pharmaceuticals which modulate the renin-angiotensin-aldosterone system. ...

References

1. ^ Physiology at MCG 7/7ch09/7ch09p16

• Brenner & Rector's The Kidney, 7th ed., Saunders, 2004.

• Mosby's Medical Dictionary, 3rd Ed., CV Mosby Company, 1990.

• Review of Medical Physiology, 20th Ed., William F. Ganong, McGraw-Hill, 2001.

In 1828 the Medical Academy of Georgia was chartered by the state of Georgia with plans to offer a single course of lectures leading to a bachelors degree. ...

External links

• MeSH Angiotensins