The alpha-1A adrenergic receptor (α_1A adrenoreceptor), also known as ADRA1A, formerly known also as the alpha-1C adrenergic receptor, is an

alpha-1 adrenergic receptor alpha-1 (α1) adrenergic are G protein-coupled receptors (GPCRs) associated with the Gq alpha subunit, Gq heterotrimeric G protein. α1-adrenergic receptors are subdivided into three highly homologous subtypes, i.e., α1A-adrenergic, α1A-, α1B ...

, and also denotes the human

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

encoding it. There is no longer a subtype α_1C receptor. At one time, there was a subtype known as α_1C, but it was found to be identical to the previously discovered α_1A receptor subtype. To avoid confusion, the naming convention was continued with the letter D.

Receptor

There are 3 alpha-1 adrenergic receptor subtypes: alpha-1A, -1B and -1D, all of which signal through the Gq/11 family of G-proteins. Different subtypes show different patterns of activation. The majority of alpha-1 receptors are directed toward the function of

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 a ...

, a hormone that has to do with the

fight-or-flight response The fight-or-flight or the fight-flight-freeze-or-fawn (also called hyperarousal or the acute stress response) is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival. It was first describ ...

Gene

This gene encodes the alpha-1A-adrenergic receptor. Alternative splicing of this gene generates four transcript variants, which encode four different isoforms with distinct C-termini but having similar ligand binding properties.

Ligands

Agonists

* 6-(5-fluoro-2-pyrimidin-5-yl-phenyl)-6,7-dihydro-5H-pyrrolo

,2-a The comma is a punctuation mark that appears in several variants in different languages. Some typefaces render it as a small line, slightly curved or straight, but inclined from the vertical; others give it the appearance of a miniature fille ...

midazole: EC₅₀ = 1nM, E_max = 65%; good selectivity over α1B, α1D and α2A subtypes * further partial agonistic imidazole compounds * A-61603 *

Metaraminol Metaraminol, also known as metaradrine and sold under the brand name Aramine among others, is a sympathomimetic medication which is used in the prevention and treatment of hypotension (low blood pressure), particularly as a complication of an ...

Antagonists

* Tamsulosin: for treatment of

benign prostatic hyperplasia Benign prostatic hyperplasia (BPH), also called prostate enlargement, is a noncancerous increase in size of the prostate gland. Symptoms may include frequent urination, trouble starting to urinate, weak stream, urinary retention, inability t ...

Silodosin Silodosin, sold under the brand name Urief among others, is a medication used for the symptomatic treatment of benign prostatic hyperplasia. It acts as an alpha-1 adrenergic receptor antagonist. The most common side effect is a reduction in the ...

: for treatment of

Doxazosin Doxazosin, sold under the brand name Cardura among others, is a medication used to treat symptoms of benign prostatic hyperplasia (enlarged prostate), hypertension (high blood pressure), and post-traumatic stress disorder (PTSD). For high bloo ...

: for treatment of

and/or

Hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

Risperidone Risperidone, sold under the brand name Risperdal among others, is an atypical antipsychotic used to treat schizophrenia and bipolar disorder, as well as aggressive and self-injurious behaviors associated with autism spectrum disorder. It is t ...

: used to treat

schizophrenia Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...

and

bipolar disorder Bipolar disorder (BD), previously known as manic depression, is a mental disorder characterized by periods of Depression (mood), depression and periods of abnormally elevated Mood (psychology), mood that each last from days to weeks, and in ...

WB-4101 WB-4101 is a compound which acts as an antagonist at the α1B-adrenergic receptor. It was one of the first selective antagonists developed for this receptor and was invented in 1969, but is still commonly used in research into adrenergic recepto ...

Ziprasidone Ziprasidone, sold under the brand name Geodon among others, is an atypical antipsychotic used to treat schizophrenia and bipolar disorder. It may be used by mouth and by injection into a muscle (IM). The intramuscular form may be used for ...

Nicergoline Nicergoline, sold under the brand name Sermion among others, is an ergot derivative used to treat senile dementia and other disorders with vascular origins. Internationally it has been used for frontotemporal dementia as well as early onset in ...

* Most

tricyclic antidepressants Tricyclic antidepressants (TCAs) are a class of medications that are used primarily as antidepressants. TCAs were discovered in the early 1950s and were marketed later in the decade. They are named after their chemical structure, which contains ...

Role in neural circuits

α1A-adrenergic receptor subtypes increase inhibition at dendrodendritic synapses, suggesting a synaptic mechanism for noradrenergic modulation of olfactory driven behaviors.

References

External links

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