Circulating and cardiac levels of apelin, the novel ligand of the orphan receptor APJ, in patients with heart failure

Biochem Biophys Res Commun. 2003 Aug 29;308(3):480-5. doi: 10.1016/s0006-291x(03)01424-4.


The orphan receptor APJ and its recently identified endogenous ligand, apelin, are expressed in the heart. However, their importance in the human cardiovascular system is not known. This study shows that apelin-like immunoreactivity is abundantly present in healthy human heart and plasma. Gel filtration HPLC analysis revealed that atrial and plasma levels of high molecular weight apelin, possibly proapelin, were markedly higher than those of mature apelin-36 itself. As assessed by quantitative RT-PCR analysis, left ventricular apelin mRNA levels were increased 4.7-fold in chronic heart failure (CHF) due to coronary heart disease (p<0.01) and 3.3-fold due to idiopathic dilated cardiomyopathy (p<0.05), whereas atrial apelin mRNA levels were unchanged. Atrial and plasma apelin-like immunoreactivity as well as atrial and ventricular APJ receptor mRNA levels were significantly decreased in CHF. Our results suggest that a new cardiac regulatory peptide, apelin, and APJ receptor may contribute to the pathophysiology of human CHF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Apelin
  • Apelin Receptors
  • Carrier Proteins / blood*
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Female
  • Heart Atria / chemistry
  • Heart Atria / metabolism
  • Heart Failure / blood*
  • Heart Failure / genetics
  • Heart Failure / metabolism*
  • Heart Ventricles / chemistry
  • Heart Ventricles / metabolism
  • Humans
  • Intercellular Signaling Peptides and Proteins
  • Ligands
  • Male
  • Middle Aged
  • Myocardium / chemistry
  • Myocardium / metabolism
  • RNA, Messenger / analysis
  • RNA, Messenger / biosynthesis
  • Radioimmunoassay
  • Receptors, Dopamine D2 / genetics
  • Receptors, Dopamine D2 / metabolism
  • Receptors, G-Protein-Coupled*


  • APLN protein, human
  • APLNR protein, human
  • Apelin
  • Apelin Receptors
  • Carrier Proteins
  • Intercellular Signaling Peptides and Proteins
  • Ligands
  • RNA, Messenger
  • Receptors, Dopamine D2
  • Receptors, G-Protein-Coupled