Urocortin 1

Where it comes from

Made in

The Edinger-Westphal nucleus of the midbrain; also gut, heart, immune cells and skin

Sent out by

Stress and inflammation; in the heart, under hypoxia

Acts on

• Hypothalamus (appetite)
• Heart muscle and vessels
• Gut
• Immune cells

What it does

• Suppresses food intake more strongly than CRH, through CRHR2
• Protects the heart in ischaemia and strengthens its beat
• Takes part in the anxiety response and in alcohol seeking in rodents

In medicine

• None; an hour-long infusion in eight men with stable heart failure raised ACTH and cortisol and changed neither cardiac output nor blood pressure ¹
• It is not measured in clinical practice, and the CRH-binding protein circulating in plasma makes it awkward to assay

Beyond the body’s own use

• Human work on urocortin 1 stopped at that single infusion study; the cousins urocortin 2 and 3 were the ones carried into heart failure trials ²
• The appetite effect that first drew interest, stronger than CRH’s and acting through CRHR2, is a rodent finding and has not been tested in people
• Gene transfer rather than infusion is the current animal approach, because the peptide’s half-life in blood is under an hour ¹