The beta-3 adrenergic receptor (β
3-adrenoceptor), also known as ADRB3, is a
beta-adrenergic receptor
The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta ...
, and also denotes the human
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
encoding it.
Function
Actions of the β
3 receptor include
*Enhancement of
lipolysis
Lipolysis is the metabolic pathway through which lipid triglycerides are hydrolyzed into a glycerol and free fatty acids. It is used to mobilize stored energy during fasting or exercise, and usually occurs in fat adipocytes. The most important ...
in
adipose tissue
Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular e ...
.
*
Thermogenesis
Thermogenesis is the process of heat production in organisms. It occurs in all warm-blooded animals, and also in a few species of thermogenic plants such as the Eastern skunk cabbage, the Voodoo lily (''Sauromatum venosum''), and the giant wate ...
in
skeletal muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
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It is located mainly in
adipose tissue
Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular e ...
and is involved in the regulation of lipolysis and
thermogenesis
Thermogenesis is the process of heat production in organisms. It occurs in all warm-blooded animals, and also in a few species of thermogenic plants such as the Eastern skunk cabbage, the Voodoo lily (''Sauromatum venosum''), and the giant wate ...
. Some β
3 agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...
s have demonstrated
antistress
Stress management is a wide spectrum of techniques and psychotherapies aimed at controlling a person's level of stress, especially chronic stress, usually for the purpose of and for the motive of improving everyday functioning. Stress produces nu ...
effects in animal studies, suggesting it also has a role in the central nervous system (CNS). β
3 receptors are found in the gallbladder, urinary bladder, and in
brown adipose tissue
Brown adipose tissue (BAT) or brown fat makes up the adipose organ together with white adipose tissue (or white fat). Brown adipose tissue is found in almost all mammals.
Classification of brown fat refers to two distinct cell populations with si ...
. Their role in gallbladder physiology is unknown, but they are thought to play a role in lipolysis and thermogenesis in brown fat. In the urinary bladder it is thought to cause relaxation of the bladder and prevention of urination.
Mechanism of action
Beta adrenergic receptors are involved in the
epinephrine
Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and ...
- and
norepinephrine
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad'', ...
-induced activation of
adenylate cyclase
Adenylate cyclase (EC 4.6.1.1, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction:
:A ...
through the action of the
G proteins
G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. Their act ...
of the type
Gs.
Ligands
Agonists
*
Amibegron (SR-58611A)
*
BRL-37344
* CL-316,243
* L-742,791
* L-796,568
* LY-368,842
*
Mirabegron
Mirabegron, sold under the brand name Myrbetriq among others, is a medication used to treat overactive bladder. Its benefits are similar to antimuscarinic medication such as solifenacin or tolterodine. It is taken by mouth.
Common side effec ...
(YM-178), approved for treatment of overactive bladder in Japan, United States, UK, Canada, China and India.
*
Nebivolol
Nebivolol is a beta blocker used to treat high blood pressure and heart failure. As with other β-blockers, it is generally a less preferred treatment for high blood pressure. It may be used by itself or with other blood pressure medication. I ...
selective beta(1)-blocker and beta(3)-agonist.
* Ro40-2148
*
Solabegron (GW-427,353)
*
Vibegron
Vibegron, sold under the brand name Gemtesa, is a medication for the treatment of overactive bladder.
Vibegron (other names: RVT-901; MK4618; KRP114V; URO-901) is a selective beta-3 adrenergic receptor agonist.
The most common side effects i ...
(MK-4618)
Antagonists
* L-748,328
* L-748,337
*
SR 59230A
SR 59230A is a selective antagonist of the beta-3 adrenergic receptor, but was subsequently shown to also act at α1 adrenoceptors at high doses. It has been shown to block the hyperthermia produced by MDMA
3,4-Methylenedioxymethamphetamine ...
was thought to be a selective β
3 antagonist
An antagonist is a character in a story who is presented as the chief foe of the protagonist.
Etymology
The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...
but later found to also be an antagonist of the α
1 receptor.
Interactions
Beta-3 adrenergic receptor has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with
Src.
See also
*Other
adrenergic receptor
The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta ...
s
**
Alpha-1 adrenergic receptor
alpha-1 (α1) adrenergic receptors are G protein-coupled receptors (GPCRs) associated with the Gq heterotrimeric G protein. α1-adrenergic receptors are subdivided into three highly homologous subtypes, i.e., α1A-, α1B-, and α1D-adrenergic ...
**
Alpha-2 adrenergic receptor
The alpha-2 (α2) adrenergic receptor (or adrenoceptor) is a G protein-coupled receptor (GPCR) associated with the Gi heterotrimeric G-protein. It consists of three highly homologous subtypes, including α2A-, α2B-, and α2C-adrenergic. Som ...
**
Beta-1 adrenergic receptor
The beta-1 adrenergic receptor (β1 adrenoceptor), also known as ADRB1, is a beta-adrenergic receptor, and also denotes the human gene encoding it. It is a G-protein coupled receptor associated with the Gs heterotrimeric G-protein and is express ...
**
Beta-2 adrenergic receptor
The beta-2 adrenergic receptor (β2 adrenoreceptor), also known as ADRB2, is a cell membrane-spanning beta-adrenergic receptor
The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catechola ...
**
Beta Blocker
Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage cardiac arrhythmia, abnormal heart rhythms, and to protect the heart from a second myocardial infarction, heart attack after a first heart ...
References
Further reading
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External links
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{{Use dmy dates, date=January 2012
Adrenergic receptors