The protein encoded by this gene acts as receptor for arginine vasopressin. This receptor belongs to the subfamily of G-protein coupled receptors which includes AVPR1A, V2R and OXT receptors. Its activity is mediated by G proteins which stimulate a phosphatidylinositol-calcium second messenger system. The receptor is primarily located in the anterior pituitary, where it stimulates ACTH release. It is expressed at high levels in ACTH-secreting pituitary adenomas as well as in bronchial carcinoids responsible for the ectopic ACTH syndrome. A spliced antisense transcript of this gene has been reported but its function is not known.AVPR1B (Arginine Vasopressin Receptor 1B) is a Protein Coding gene. Diseases associated with AVPR1B include Acth-Independent Macronodular Adrenal Hyperplasia and Melancholia. Among its related pathways are Peptide ligand-binding receptors and Vascular smooth muscle contraction. GO annotations related to this gene include G-protein coupled receptor activity and protein kinase C binding. An important paralog of this gene is OXTR.