Alpha-1A adrenergic receptor

Transduction mechanisms
Agonists
Antagonists
Inverse agonists
Positive allosteric modulators
Negative allosteric modulators

The alpha-1A adrenergic receptor (ADRA1A) is a type of adrenergic receptor that is primarily involved in vasoconstriction and pupil dilation. It is a G protein-coupled receptor (GPCR) that is activated by catecholamines, mainly norepinephrine (noradrenaline) and to a lesser extent epinephrine (adrenaline). This receptor plays a significant role in regulating blood pressure, smooth muscle tone, and other physiological functions.

Function

The alpha-1A adrenergic receptor is predominantly found in the vascular smooth muscle, where its activation leads to vasoconstriction, thereby increasing blood pressure. It is also present in the eye, where it contributes to pupil dilation (mydriasis) by contracting the radial muscle of the iris. Additionally, it is involved in the contraction of other smooth muscles, such as those in the bladder and prostate, which is why medications targeting this receptor can be used to treat conditions like urinary retention and benign prostatic hyperplasia (BPH).

Pharmacology

Pharmacologically, the alpha-1A adrenergic receptor is targeted by various drugs, including alpha blockers, which are used to treat high blood pressure and BPH. These drugs work by blocking the receptor, thereby preventing norepinephrine from causing vasoconstriction and smooth muscle contraction.

Genetics

The gene encoding the alpha-1A adrenergic receptor, ADRA1A, is located on the human chromosome 8. Variations in this gene can affect the receptor's function and expression, potentially influencing an individual's susceptibility to cardiovascular diseases and their response to certain medications.

Clinical Significance

Alterations in alpha-1A adrenergic receptor function or expression can contribute to various cardiovascular and urological conditions. Understanding the role of this receptor in disease has led to the development of targeted therapies that can alleviate symptoms and improve quality of life for affected individuals.

See Also

• Adrenergic receptor
• G protein-coupled receptor
• Vasoconstriction
• Benign prostatic hyperplasia