Apelin

also known as: APLN, Apelin-13, Apelin-36, Pyr-Apelin-13

A cardiovascular protective peptide — opposes the harmful effects of angiotensin II, promotes cardiac contractility, and is an emerging target for heart failure therapeutics.

An endogenous peptide ligand for the APJ receptor (a GPCR structurally related to the angiotensin II receptor), with inotropic, vasodilatory, and cardioprotective effects that functionally antagonize the RAAS system.

Mechanism of action

Agonist at the APJ receptor (Apelin receptor, a Gi/Gq-coupled GPCR). Increases cardiac contractility (positive inotrope) without hypertrophy, promotes vasodilation via endothelial NO release, opposes angiotensin II-mediated vasoconstriction and fibrosis, stimulates angiogenesis, and has glucose-lowering effects. ACE2 is both a processing enzyme and regulator of the apelin system.

Primary uses

Cardiovascular physiology research
Heart failure therapeutic target
Pulmonary hypertension research
Metabolic syndrome studies

Typical dosing

Not established

Research compound. No established therapeutic dosing.

Regulatory status

Not approved. Synthetic apelin analogs are in early clinical development for heart failure and pulmonary arterial hypertension.

References

[pubmed] Tatemoto K, et al. "Isolation and characterization of a novel endogenous peptide ligand for the human APJ receptor." Biochem Biophys Res Commun, 1998;251:471-476.
[review] Kleinz MJ, Davenport AP. "Emerging roles of apelin in biology and medicine." Pharmacol Ther, 2005;107:198-211.

Related peptides

Angiotensin II

Giapreza — the first new vasopressor class approved in decades. FDA-approved December 2017 (La Jolla Pharmaceutical) for catecholamine-resistant septic / distributive shock based on the ATHOS-3 trial (NEJM 2017, n=321). Engages a third vasoconstrictor pathway (RAAS / AT1) independent of catecholamines and vasopressin — useful when both of those axes are desensitised.

BNP

The heart failure biomarker — an endogenous cardiac peptide whose blood levels are the gold standard for diagnosing and monitoring heart failure severity.

ANP

The atrial pressure sensor — the first discovered natriuretic peptide, maintaining blood pressure and fluid balance through renal sodium excretion and vasodilation.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.