Neuromedin U

Where it comes from

Made in

Gut lining, hypothalamus, pituitary, immune cells

Sent out by

Poorly defined; circadian in the hypothalamus

Acts on

• Uterus and gut smooth muscle
• Hypothalamus (feeding, stress)
• Type 2 innate lymphoid cells in the gut

What it does

• Contracts smooth muscle (it was named for the uterus)
• Reduces food intake and raises energy expenditure in animals ¹
• Amplifies allergic-type immune responses in the gut: nerves release it and type 2 innate lymphoid cells answer within minutes ²

In medicine

• None. NMU gene variants are linked with obesity in genetic studies, and no clinical assay measures the peptide ¹
• The immune work has no clinical use yet, though it ties the nervous system to allergic inflammation in a way that drug makers are watching ²

Beyond the body’s own use

• Long-acting NMUR2 agonists cut weight in obese mice and none has reached people. The obstacle is NMUR1 in the periphery, which raises blood pressure and contracts smooth muscle, so a usable medicine has to miss it ¹
• The nerve-to-immune-cell finding is the live one: deleting the receptor on those cells blunted the response to a parasite, which suggests the peptide is a switch rather than a modulator ²