Neuromedin U receptor 1 (NMUR1) is a member of G-protein coupled receptor family A and is the most abundant in peripheral tissue, particularly in small intestines and stomach. This protein is a receptor for Neuromedin U (NMU-25). The first biological activity ascribed to NmU was smooth muscle contraction. Neuromedin U has also been reported to increase arterial blood pressure and modify ion transport in the intestinal tract. Finally, NmU injected subcutaneously into rats has been reported to result in a short term increase in circulating ACTH levels and a long term increase in serum corticosterone levels, suggesting a role in regulation of the hypothalamo-pituitary-adrenal axis.