Target type: biologicalprocess
The process in which the diameter of a blood vessel is changed due to activity of the renin-angiotensin system. [GOC:dph, GOC:pr, GOC:tb]
The renin-angiotensin system (RAS) plays a critical role in maintaining blood vessel diameter homeostasis, ensuring adequate blood flow to tissues. This intricate system involves a cascade of enzymatic reactions that ultimately lead to the production of angiotensin II, a potent vasoconstrictor.
**Here's a breakdown of the process:**
1. **Renin Release:** When blood pressure or blood flow decreases, specialized cells in the kidneys called juxtaglomerular cells release renin.
2. **Angiotensinogen Conversion:** Renin converts angiotensinogen, a precursor protein produced by the liver, into angiotensin I.
3. **Angiotensin I to Angiotensin II:** Angiotensin I is further converted into angiotensin II by angiotensin-converting enzyme (ACE), primarily found in the lungs.
4. **Vasoconstriction:** Angiotensin II binds to its receptors (AT1 and AT2) on vascular smooth muscle cells. This binding triggers a signaling cascade that leads to smooth muscle cell contraction, causing vasoconstriction and an increase in blood pressure.
**Beyond vasoconstriction, angiotensin II contributes to blood vessel diameter homeostasis through other mechanisms:**
* **Aldosterone Release:** Angiotensin II stimulates the release of aldosterone from the adrenal glands, leading to sodium retention and water reabsorption. This increases blood volume and contributes to blood pressure elevation.
* **Sodium Retention:** Angiotensin II directly promotes sodium reabsorption in the kidneys, further contributing to blood volume expansion.
* **Sympathetic Nervous System Activation:** Angiotensin II activates the sympathetic nervous system, which further increases heart rate and contractility, enhancing blood pressure.
**Counterbalancing Mechanisms:**
While angiotensin II acts as a vasoconstrictor, other mechanisms counteract its effects, ensuring proper blood vessel diameter regulation:
* **Nitric Oxide (NO):** NO is a potent vasodilator released by endothelial cells lining blood vessels. Its release is stimulated by various factors, including shear stress from blood flow, counteracting the vasoconstriction effects of angiotensin II.
* **Prostaglandins:** These lipid mediators are involved in various physiological processes, including vasodilation. Some prostaglandins can counteract the vasoconstrictive actions of angiotensin II.
**Overall, the renin-angiotensin system is tightly regulated to maintain blood vessel diameter and blood pressure within a healthy range. Imbalances in this system can lead to various cardiovascular diseases, highlighting its critical importance in maintaining overall health.**'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Type-1 angiotensin II receptor | An angiotensin II receptor 1 that is encoded in the genome of cow. [OMA:P25104, PRO:DNx] | Bos taurus (cattle) |
| Type-1 angiotensin II receptor | An angiotensin II receptor 1 that is encoded in the genome of human. [PRO:WCB, UniProtKB:P30556] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| 5-iodo-2-(oxaloamino)benzoic acid | organoiodine compound | ||
| candesartan | candesartan : A benzimidazolecarboxylic acid that is 1H-benzimidazole-7-carboxylic acid substituted by an ethoxy group at position 2 and a ({2'-(1H-tetrazol-5-yl)[1,1'-biphenyl]-4-yl}methyl) group at position 1. It is a angiotensin receptor antagonist used for the treatment of hypertension. candesartan: a nonpeptide angiotensin II receptor antagonist | benzimidazolecarboxylic acid; biphenylyltetrazole | angiotensin receptor antagonist; antihypertensive agent; environmental contaminant; xenobiotic |
| thiorphan | Thiorphan: A potent inhibitor of membrane metalloendopeptidase (ENKEPHALINASE). Thiorphan potentiates morphine-induced ANALGESIA and attenuates naloxone-precipitated withdrawal symptoms. | N-acyl-amino acid | |
| avapro | irbesartan : A biphenylyltetrazole that is an angiotensin II receptor antagonist used mainly for the treatment of hypertension. Irbesartan: A spiro compound, biphenyl and tetrazole derivative that acts as an angiotensin II type 1 receptor antagonist. It is used in the management of HYPERTENSION, and in the treatment of kidney disease. | azaspiro compound; biphenylyltetrazole | angiotensin receptor antagonist; antihypertensive agent; environmental contaminant; xenobiotic |
| losartan | losartan : A biphenylyltetrazole where a 1,1'-biphenyl group is attached at the 5-position and has an additional trisubstituted imidazol-1-ylmethyl group at the 4'-position Losartan: An antagonist of ANGIOTENSIN TYPE 1 RECEPTOR with antihypertensive activity due to the reduced pressor effect of ANGIOTENSIN II. | biphenylyltetrazole; imidazoles | angiotensin receptor antagonist; anti-arrhythmia drug; antihypertensive agent; endothelin receptor antagonist |
| propranolol | propranolol : A propanolamine that is propan-2-ol substituted by a propan-2-ylamino group at position 1 and a naphthalen-1-yloxy group at position 3. Propranolol: A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs. | naphthalenes; propanolamine; secondary amine | anti-arrhythmia drug; antihypertensive agent; anxiolytic drug; beta-adrenergic antagonist; environmental contaminant; human blood serum metabolite; vasodilator agent; xenobiotic |
| atomoxetine | atomoxetine : A secondary amino compound having methyl and 3-(2-methylphenoxy)-3-phenylpropan-1-yl substituents. | aromatic ether; secondary amino compound; toluenes | adrenergic uptake inhibitor; antidepressant; environmental contaminant; xenobiotic |
| ipsapirone | N-arylpiperazine | ||
| flesinoxan | |||
| valsartan | valsartan : A monocarboxylic acid amide consisting of L-valine in which the amino hydrogens have been replaced by a pentanoyl and a [2'-(1H-tetrazol-5-yl)biphenyl]-4-yl]methyl group. It exhibits antihypertensive activity. Valsartan: A tetrazole derivative and ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKER that is used to treat HYPERTENSION. | biphenylyltetrazole; monocarboxylic acid; monocarboxylic acid amide | angiotensin receptor antagonist; antihypertensive agent; environmental contaminant; xenobiotic |
| tasosartan | tasosartan: angiotensin II antagonist; structure given in first source | biphenyls | |
| telmisartan | telmisartan : A member of the class of benzimidazoles used widely in the treatment of hypertension. Telmisartan: A biphenyl compound and benzimidazole derivative that acts as an angiotensin II type 1 receptor antagonist. It is used in the management of HYPERTENSION. | benzimidazoles; biphenyls; carboxybiphenyl | angiotensin receptor antagonist; antihypertensive agent; EC 3.4.15.1 (peptidyl-dipeptidase A) inhibitor; environmental contaminant; xenobiotic |
| gr 117289 | GR 117289: angiotensin AT1 receptor antagonist; structure given in first source zolasartan : A member of the class of 1-benzofurans that is 3-bromo-1-benzofuran which is substituted by a 2-(1H-tetrazol-5-yl)phenyl group at position 2 and by a (2-butyl-5-carboxy-4-chloro-1H-imidazol-1-yl)methyl group at position 5. It is an angiotensin II receptor type 1 (AT1) antagonist and was in clinical trials for the treatment of hypertension (now discontinued). | 1-benzofurans; biaryl; imidazolyl carboxylic acid; monocarboxylic acid; organobromine compound; organochlorine compound; tetrazoles | angiotensin receptor antagonist; antihypertensive agent |
| exp3174 | losartan carboxylic acid : A biphenylyltetrazole that is losartan with the hydroxymethyl group at position 5 on the imidazole ring replaced with a carboxylic acid. losartan carboxylic acid: structure given in first source | biphenylyltetrazole; imidazoles; organochlorine compound | metabolite |
| l 692429 | L 692429: stimulates release of growth hormone; RN refers to (R)-isomer; structure given in first source | ||
| angiotensin ii, des-asp(1)-des-arg(2)-ile(5)- | angiotensin II, des-Asp(1)-des-Arg(2)-Ile(5)-: 3-8 hexapeptide fragment of angiotensin II; smallest potent angiotensin II antagonist | organic molecular entity | |
| exp7711 | EXP7711: to search, use E#P7711(nm); angiotensin II receptor antagonist; structure given in first source | ||
| bibs 39 | BIBS 39: structure given in first source; angiotensin II receptor antagonist | ||
| bibs 222 | BIBS 222: structure given in first source; angiotensin II receptor antagonist | ||
| forasartan | forasartan : A member of the class of pyridines that is pyridine which is substituted at positions 2 and 5 by o-(tetrazol-5-yl)phenyl and (3,5-dibutyl-1,2,4-triazol-1-yl)methyl groups, respectively. It is a nonpeptide antagonist of angiotensin II, type 1 (AT1) receptors, used for the treatment of hypertension. forasartan: structure given in first source; an angiotensin AT(1) receptor antagonist; angiotensin II receptor antagonist; used in treatment of congestive heart failure | benzenes; pyridines; tetrazoles; triazoles | angiotensin receptor antagonist; antihypertensive agent |
| up 269-6 | UP 269-6: structure given in first source; angiotensin receptor antagonist | ||
| mk 996 | MK 996: an AT1-selective angiotensin II receptor antagonist; structure given in first source | ||
| bms 207940 | N-((2'-(((4,5-dimethyl-3-isoxazolyl)amino)sulfonyl)-4-(2-oxazolyl)(1,1'-biphenyl)-2-yl)methyl)-N,3,3-trimethylbutanamide: an ET(A) receptor antagonist; structure in first source | ||
| angiotensin ii | Giapreza: injectable form of angiotensin II used to increase blood pressure in adult patients with septic or other distributive shock Ile(5)-angiotensin II : An angiotensin II that acts on the central nervous system (PDB entry: 1N9V). | amino acid zwitterion; angiotensin II | human metabolite |
| piboserod | Serotonin 5-HT4 Receptor Antagonists: Drugs that bind to but do not activate SEROTONIN 5-HT4 RECEPTORS, thereby blocking the actions of SEROTONIN or SEROTONIN RECEPTOR AGONISTS. | ||
| l 158809 | L 158809: RN & structure given in first source; angiotensin receptor antagonist | ||
| 2-(oxaloamino)benzoic acid | (oxaloamino)benzoic acid | ||
| omapatrilat | omapatrilat: structure in first source | dipeptide | |
| caffeic acid | trans-caffeic acid : The trans-isomer of caffeic acid. | caffeic acid | geroprotector; mouse metabolite |
| cv 11194 | CV 11194: structure given in first source; an angiotensin II receptor antagonist | ||
| milfasartan | milfasartan: angiotensin I receptor antagonist; structure in first source | ||
| eprosartan | eprosartan : A member of the class of imidazoles and thiophenes that is an angiotensin II receptor antagonist used for the treatment of high blood pressure. eprosartan: angiotensin II receptor antagonist | dicarboxylic acid; imidazoles; thiophenes | angiotensin receptor antagonist; antihypertensive agent; environmental contaminant; xenobiotic |
| pd 123319 | PD123319 : An imidazopyridine consisting of 4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine having 4-(dimethylamino)-3-methylbenzyl, diphenylacetyl and carboxy and groups at positions 1, 5 and 6 respectively | imidazopyridine | angiotensin receptor antagonist; endothelin receptor antagonist; vasoconstrictor agent |
| exp 655 | |||
| angiotensin ii, 1-sar-5-ile-8-ala- | |||
| saralasin | Saralasin: An octapeptide analog of angiotensin II (bovine) with amino acids 1 and 8 replaced with sarcosine and alanine, respectively. It is a highly specific competitive inhibitor of angiotensin II that is used in the diagnosis of HYPERTENSION. | oligopeptide | |
| l 162313 | L 162313: a biphenylimidazole derivative; a non-peptide angiotensin agonist; no further information available 2/95 | ||
| 4-oxo-6-((pyrimidin-2-ylthio)methyl)-4h-pyran-3-yl 4-nitrobenzoate | 4-oxo-6-((pyrimidin-2-ylthio)methyl)-4H-pyran-3-yl 4-nitrobenzoate: structure in first source | nitrobenzoic acid | |
| zd 7155 | |||
| bms 193884 | |||
| l 163491 | L 163491: structure given in first source | ||
| fimasartan | fimasartan: an angiotensin II receptor antagonist | biphenyls | |
| bms 248360 | |||
| ema401 | |||
| naluzotan | naluzotan: an antidepressant and anti-anxiety agent; structure in first source | ||
| nitd 609 | NITD 609: an antimalarial and coccidiostat; structure in first source |