AVPR - Arginine Vasopressin Receptor | Elisa - Clia - Antibody - Protein

Background

The Arginine Vasopressin Receptor (AVPR), also known as the Vasopressin Receptor, is a class A G protein-coupled receptor (GPCR) that mediates the actions of arginine vasopressin (AVP), also called antidiuretic hormone (ADH). AVPRs are essential for regulating water reabsorption in the kidneys and play critical roles in various physiological processes, including blood pressure regulation, osmotic balance, and social behavior. The primary ligand for AVPRs is arginine vasopressin (AVP), a peptide hormone produced by the hypothalamus and released from the posterior pituitary gland in response to changes in osmotic pressure or blood volume. AVP binds to AVPRs with high affinity and specificity, triggering downstream signaling cascades. In summary, the Arginine Vasopressin Receptors (AVPRs) play critical roles in regulating water balance, blood pressure, stress responses, and social behavior. Dysregulation of AVPR signaling is implicated in various clinical conditions, making AVPRs potential targets for therapeutic intervention across a range of disorders

Structural Features:

AVPRs belong to the class A rhodopsin-like family of GPCRs and possess seven transmembrane helices, an extracellular N-terminus, and an intracellular C-terminus. They exhibit high sequence homology and are encoded by separate genes.

Subtypes:

There are three known subtypes of AVPRs:

1.   V1A Receptor (AVPR1A): Expressed in vascular smooth muscle cells, where it mediates vasoconstriction, and in the brain, where it influences social behavior and aggression.

2.   V1B Receptor (AVPR1B): Primarily expressed in the pituitary gland, where it regulates adrenocorticotropic hormone (ACTH) release in response to stress.

3.   V2 Receptor (AVPR2): Expressed in the renal collecting ducts, where it mediates the antidiuretic effects of AVP by promoting water reabsorption.

Physiological Functions:

1.   Water Reabsorption: AVPR2 mediates the antidiuretic effects of AVP in the kidneys by promoting water reabsorption in the renal collecting ducts, thereby reducing urine output and maintaining water balance.

2.   Vasoconstriction: AVPR1A mediates the vasoconstrictive effects of AVP in vascular smooth muscle cells, contributing to blood pressure regulation and vascular tone.

3.   Stress Response: AVPR1B in the pituitary gland regulates the release of adrenocorticotropic hormone (ACTH) in response to stress, leading to cortisol secretion from the adrenal glands.

4.   Social Behavior: AVPR1A in the brain is implicated in the regulation of social behavior, including pair bonding, maternal behavior, aggression, and affiliative behaviors.

Clinical Implications:

1.   Diabetes Insipidus: Mutations or dysregulation of AVPR2 can lead to nephrogenic diabetes insipidus, a disorder characterized by impaired renal response to AVP and excessive urination.

2.   Hypotension: Dysfunctional AVPR1A signaling may contribute to hypotension or vasodilatory shock, while overactivation may lead to hypertension.

3.   Stress-Related Disorders: Dysregulation of AVPR1B signaling has been implicated in stress-related disorders such as anxiety, depression, and post-traumatic stress disorder (PTSD).

4.   Social and Behavioral Disorders: Variations in AVPR1A function have been associated with social and behavioral disorders, including autism spectrum disorder (ASD) and schizophrenia.

Therapeutic Potential:

1.   Vasopressin Receptor Agonists: Synthetic AVP analogs and AVPR agonists are used clinically to treat conditions such as diabetes insipidus, hypotension, and bleeding disorders.

2.   Vasopressin Receptor Antagonists: AVPR antagonists are being investigated as potential therapeutics for conditions such as hyponatremia, heart failure, and polycystic kidney disease.

3.   Neurological and Psychiatric Disorders: Modulating AVPR1A and AVPR1B signaling pathways may offer novel therapeutic approaches for the treatment of stress-related disorders, social and behavioral disorders, and mood disorders.

Summary:

Arginine Vasopressin Receptors (AVPRs) are essential GPCRs that mediate the effects of arginine vasopressin, influencing water balance, blood pressure, and the stress response. The three main subtypes, AVPR1A, AVPR1B, and AVPR2, have distinct roles and tissue distributions, contributing to various physiological processes. Dysregulation of these receptors can lead to conditions such as diabetes insipidus, SIADH, hypertension, and stress-related disorders, making them critical targets for therapeutic interventions.