Urotensin II (human) (trifluoroacetate salt)

Urotensin II is a somatostatin-like neuropeptide agonist of the urotensin II receptor (UTR; Ki = 2 nM). It increases intracellular calcium levels in a concentration-dependent manner in HEK293 cells expressing human UTR (EC50 = 0.6 nM). Urotensin II increases the level of reactive oxygen species (ROS) in pulmonary artery smooth muscle cells and induces proliferation, an effect that is inhibited by depletion of NADPH oxidase subunits. Urotensin II potently induces contraction of isolated rat thoracic aorta with an EC50 of 0.8 nM. It also induces contraction of isolated cynomolgus monkey arterial, but not venous, vessels and, when administered at doses greater than 100 pmol/kg, can lead to severe myocardial depression and fatal circulatory collapse.