Prolactin-releasing peptide-31

Where it comes from

Made in

The same brainstem and hypothalamic neurons as PrRP-20

Sent out by

With PrRP-20; the two are cut from one precursor

Acts on

• Hypothalamus
• Brainstem

What it does

• Suppresses feeding and raises blood pressure as PrRP-20 does, somewhat more potently ¹
• Carries satiety from the brainstem to the hypothalamus after a meal, alongside CCK ²
• Takes part in the stress response by acting on CRH neurons of the paraventricular nucleus ²

In medicine

• None of its own; no PrRP-31 medicine or clinical assay exists
• Telling the two forms apart is the practical difficulty, because most antibodies recognise the shared amidated tail, so a reported PrRP level usually means both ²

Beyond the body’s own use

• No human trial; what is known comes from rodents given the peptide into the brain or the bloodstream ²
• PrRP-31 is the form the lipidised anti-obesity analogues were built from, and those reduced weight and improved glucose tolerance across several rodent models of obesity and metabolic syndrome ³
• Whether the two forms do different jobs is unsettled. Both act on GPR10, PrRP-31 rather more strongly, and no tool selective for one of them exists ¹