Vasopressin

Vasopressin is a cyclic nine-peptide synthesized in the hypothalamus center. Vasopressin participates in the hypothalamic-pituitary-adrenal axis and regulates pituitary corticotropin secretion by enhancing the stimulating effect of corticotropin-releasing factor. Vasopressin can also act as a neurotransmitter, acting by binding to specific G-protein-coupled receptors.