Exercise training promotes expression of apelin and APJ of cardiovascular tissues in spontaneously hypertensive rats

Life Sci. 2006 Aug 15;79(12):1153-9. doi: 10.1016/j.lfs.2006.03.040. Epub 2006 Apr 15.


Because apelin may play an important regulatory role in human cardiac dysfunction, we investigated alterations in cardiovascular content of apelin and its receptor, APJ, during hypertension and the effect of exercise training on the cardiovascular apelin/APJ system in hypertensive animals. Spontaneously hypertensive rats (SHRs) underwent swimming training consisting of 54 swimming sessions of 60 min each (6 days/week for 9 weeks). Systolic blood pressure (SBP) was verified weekly by tail-cuff plethysmography. Apelin levels in plasma and cardiovascular tissues were determined by radioimmunoassay. The level of apelin/APJ mRNA was determined by RT-PCR. SHRs showed severe hypertension and pathological cardiomegaly. The level of apelin immunoreactivity (apelin-ir) in plasma and ventricular and aortic tissues was lower, by 40%, 40% and 42% (all P<0.01), respectively, in SHRs than in control Wistar-Kyoto rats, and the mRNA level of apelin and APJ in myocardium and aorta was markedly decreased. Compared with sedentary SHRs, swimming-trained SHRs showed decreased SBP and elevated mRNA expression of apelin and APJ in cardiovascular tissues and elevated apelin-ir level in plasma, myocardium and aorta (all P<0.01). SBP and level of apelin-ir in plasma and cardiovascular tissues were negatively correlated. Long-term swimming training relieved the pathogenesis of hypertension and reversed the downregulation of the cardiovascular apelin/APJ system induced by hypertension, which suggests that the improving effect of exercise training on hypertension could be mediated by upregulating the cardiovascular apelin/APJ system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta / metabolism
  • Apelin
  • Apelin Receptors
  • Blood Pressure / physiology
  • Cardiomegaly / pathology
  • Cardiovascular System / drug effects
  • Cardiovascular System / metabolism*
  • Cardiovascular System / pathology
  • Carrier Proteins / biosynthesis*
  • Intercellular Signaling Peptides and Proteins
  • Male
  • Myocardium / metabolism
  • Myocardium / pathology
  • Natriuretic Peptide, Brain / metabolism
  • Physical Conditioning, Animal / physiology*
  • Rats
  • Rats, Inbred SHR
  • Rats, Inbred WKY
  • Receptors, G-Protein-Coupled / biosynthesis*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Swimming / physiology
  • Up-Regulation / physiology


  • Apelin
  • Apelin Receptors
  • Apln protein, rat
  • Aplnr protein, rat
  • Carrier Proteins
  • Intercellular Signaling Peptides and Proteins
  • Receptors, G-Protein-Coupled
  • Natriuretic Peptide, Brain