Peptide directoryHeart, vessels & kidneys

Apelin-36

The longest apelin, strongest in the lung and the placenta.

Where it comes from

Made in
Lung, testis and uterus, which hold mostly the long form in rats
Sent out by
With the other apelins; trimmed to the shorter forms in blood
Acts on
  • Vessels
  • Heart
  • Fat tissue

What it does

  • Less potent than the short forms at the receptor but longer-lived 1
  • Secreted in quantity into colostrum and milk by the mammary gland, where it is the main apelin present 2
  • Lowers blood pressure and raises cardiac output in animals, as the shorter forms do 1

In medicine

  • No medicine and no test. No clinical assay reports it separately from the shorter apelins
  • The one place it is clearly the main form is milk, and what it does to a nursing infant’s gut is not known 2

Beyond the body’s own use

  • It was the first apelin isolated, from cattle stomach extracts, and the shorter forms were recognised afterwards as the more potent ones; that order is why much older literature says apelin and means this 1
  • Nothing involving apelin-36 is in trials, and the long-acting analogues under study are built on apelin-13 rather than on it
  • The claim worth checking is the milk one. Apelin in colostrum is cited in work on infant gut development, but the evidence is the measurement, not an outcome in a child 2

Sources

  1. Tatemoto et al., Isolation of a novel endogenous peptide ligand for the human APJ receptor, Biochemical and Biophysical Research Communications 1998
  2. Habata et al., Apelin, the natural ligand of the orphan receptor APJ, is abundantly secreted in the colostrum, Biochimica et Biophysica Acta 1999

This card describes what a medicine is for and what the evidence says; it recommends nothing. Talk to your clinician about anything you read here.