Journal of Molecular Medicine

, Volume 90, Issue 1, pp 31–43

Therapeutic inhibition of fatty acid oxidation in right ventricular hypertrophy: exploiting Randle’s cycle

  • Yong-Hu Fang
  • Lin Piao
  • Zhigang Hong
  • Peter T. Toth
  • Glenn Marsboom
  • Peter Bache-Wiig
  • Jalees Rehman
  • Stephen L. Archer
Original Article

DOI: 10.1007/s00109-011-0804-9

Cite this article as:
Fang, YH., Piao, L., Hong, Z. et al. J Mol Med (2012) 90: 31. doi:10.1007/s00109-011-0804-9

Abstract

Right ventricular hypertrophy (RVH) and RV failure are major determinants of prognosis in pulmonary hypertension and congenital heart disease. In RVH, there is a metabolic shift from glucose oxidation (GO) to glycolysis. Directly increasing GO improves RV function, demonstrating the susceptibility of RVH to metabolic intervention. However, the effects of RVH on fatty acid oxidation (FAO), the main energy source in adult myocardium, are unknown. We hypothesized that partial inhibitors of FAO (pFOXi) would indirectly increase GO and improve RV function by exploiting the reciprocal relationship between FAO and GO (Randle’s cycle). RVH was induced in adult Sprague-Dawley rats by pulmonary artery banding (PAB). pFOXi were administered orally to prevent (trimetazidine, 0.7 g/L for 8 weeks) or regress (ranolazine 20 mg/day or trimetazidine for 1 week, beginning 3 weeks post-PAB) RVH. Metabolic, hemodynamic, molecular, electrophysiologic, and functional comparisons with sham rats were performed 4 or 8 weeks post-PAB. Metabolism was quantified in RV working hearts, using a dual-isotope technique, and in isolated RV myocytes, using a Seahorse Analyzer. PAB-induced RVH did not cause death but reduced cardiac output and treadmill walking distance and elevated plasma epinephrine levels. Increased RV FAO in PAB was accompanied by increased carnitine palmitoyltransferase expression; conversely, GO and pyruvate dehydrogenase (PDH) activity were decreased. pFOXi decreased FAO and restored PDH activity and GO in PAB, thereby increasing ATP levels. pFOXi reduced the elevated RV glycogen levels in RVH. Trimetazidine and ranolazine increased cardiac output and exercise capacity and attenuated exertional lactic acidemia in PAB. RV monophasic action potential duration and QTc interval prolongation in RVH normalized with trimetazidine. pFOXi also decreased the mild RV fibrosis seen in PAB. Maladaptive increases in FAO reduce RV function in PAB-induced RVH. pFOXi inhibit FAO, which increases GO and enhances RV function. Trimetazidine and ranolazine have therapeutic potential in RVH.

Keywords

Pulmonic stenosis Monophasic action potential duration QTc interval Myocardial fibrosis Right heart failure 

Supplementary material

109_2011_804_MOESM1_ESM.pdf (157 kb)
ESM 1(PDF 157 kb)

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Yong-Hu Fang
    • 1
  • Lin Piao
    • 1
  • Zhigang Hong
    • 1
  • Peter T. Toth
    • 1
  • Glenn Marsboom
    • 1
  • Peter Bache-Wiig
    • 2
  • Jalees Rehman
    • 3
  • Stephen L. Archer
    • 1
  1. 1.Medicine/CardiologyUniversity of ChicagoChicagoUSA
  2. 2.Department of BiologyUniversity of WisconsinMadisonUSA
  3. 3.Department of Medicine (Cardiology)University of IllinoisChicagoUSA