Vasopressin and oxytocin receptors (AVPR/OXTR)

The vasopressin and oxytocin receptor family comprises four closely related G protein-coupled receptors: the oxytocin receptor (OXTR) and three vasopressin receptor subtypes (V1aR, V1bR, and V2R) (Gimpl & Fahrenholz, 2001). These receptors exhibit high structural homology, particularly between OXTR and V1aR (~85%), which results in significant pharmacological cross-reactivity where the ligands oxytocin and arginine vasopressin can activate each other's canonical receptors at high concentrations (Song & Albers, 2017). Biologically, these receptors are essential for regulating water homeostasis (V2R), vascular resistance (V1aR), uterine contractions and milk ejection (OXTR), and the hypothalamic-pituitary-adrenal axis response to stress (V1bR) (NIH, 2023). They play critical roles in various diseases, including diabetes insipidus, hyponatremia, preterm labor, and potentially social-behavioral disorders like autism (Song & Albers, 2017). Therapeutic strategies utilize agonists such as desmopressin for polyuria and antagonists like tolvaptan for hyponatremia or atosiban for delaying preterm labor. A major challenge in drug development for this family is achieving high selectivity to avoid adverse effects stemming from cross-reactivity, such as the potential for oxytocin to cause water retention via V2R activation (Deranged Physiology, 2023).

Other names

Arginine vasopressin and oxytocin receptorsV1a, V1b, V2, and OT receptorsNeurohypophysial hormone receptorsVasopressin/oxytocin receptor family

Drugs targeting these receptors act as either agonists to mimic the effects of endogenous peptides (e.g., desmopressin for V2R-mediated water retention) or antagonists to block receptor activation (e.g., vaptans for V2R-mediated hyponatremia or atosiban for OTR-mediated uterine contractions).