Urotensin II

Where it comes from

Made in

Motor neurons of the spinal cord and brainstem, kidney, heart, endothelium

Sent out by

Poorly defined; blood levels rise in heart failure, kidney failure, diabetes and cirrhosis

Acts on

• Arteries (constriction in some beds, dilation in others)
• Heart
• Kidney
• Pancreatic beta cells

What it does

• Constricts isolated arteries more strongly than endothelin-1, yet does little to blood pressure in healthy people ¹
• Promotes heart and vessel remodelling ³
• Inhibits insulin release from the beta cells of the pancreas ³

In medicine

• No medicine. Palosuran, a UT blocker, changed neither albuminuria nor blood pressure in a 54-patient crossover trial in diabetic nephropathy ²
• No clinical test either. Plasma urotensin II rises in heart failure, kidney failure, diabetes and cirrhosis, but the assays are research-grade and disagree with one another ³

Beyond the body’s own use

• The gap between the bench and the body is the thing to know: it constricts an isolated artery more strongly than endothelin-1 and yet barely moves blood pressure when infused into a healthy person ¹
• Since palosuran, no urotensin antagonist has gone into a trial. The target has not been refuted so much as left alone ²
• It is studied as a marker in heart failure and cirrhosis, where higher levels track worse disease without adding anything to the tests already in use ³