Cardiac peroxisome proliferator-activated receptor δ (PPARδ) as a new target for increased contractility without

Zhih-Cherng Chen1, Kung Shing Lee, Li-Jen Chen

  • 1Department of Cardiology, Chi-Mei Medical Center, Yong Kang, Tainan City, Taiwan.

Plos One
|June 1, 2013
PubMed
Abstract

Insights

Peroxisome proliferator-activated receptor delta (PPARδ) activation enhances cardiac contractility without altering heart rate. This suggests PPARδ is a potential therapeutic target for heart failure treatment, offering improved heart function without side effects on heart rate.

Area of Science:

  • Cardiology
  • Molecular Biology
  • Pharmacology

Background:

  • Positive inotropic agents treat heart failure but affect heart rate.
  • Peroxisome proliferator-activated receptor delta (PPARδ) involvement in cardiac contraction is known, but its effect on heart rate is unclear.

Purpose of the Study:

  • To investigate the effect of PPARδ activation on heart rate using the agonist GW0742.
  • To determine if PPARδ can enhance cardiac contractility without affecting heart rate.

Main Methods:

  • Isolated hearts (Langendorff apparatus) and catheterized rats were used for in vitro and in vivo hemodynamic analysis.
  • Intracellular calcium levels and troponin I phosphorylation were measured using Western blotting.
  • The effects of GW0742 were assessed in normal and diabetic rats with heart failure, with and without the PPARδ blocker GSK0660.

Main Results:

  • GW0742 activated PPARδ, reversing cardiac contraction in diabetic rats with heart failure without changing heart rate.
  • In normal rats, GW0742 significantly enhanced cardiac contractility and dP/dtmax more than dobutamine, an effect blocked by GSK0660.
  • GW0742 increased intracellular calcium and troponin I phosphorylation, but did not alter heart rate, only mildly increasing blood pressure.

Conclusions:

  • PPARδ activation by GW0742 enhances cardiac contractility.
  • PPARδ activation does not affect heart rate.
  • PPARδ represents a promising therapeutic target for developing heart failure treatments with improved cardiac contractility and no heart rate side effects.

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