Dichloroacetate prevents and reverses pulmonary hypertension by inducing pulmonary artery smooth muscle cell apoptosis

Circ Res. 2004 Oct 15;95(8):830-40. doi: 10.1161/01.RES.0000145360.16770.9f. Epub 2004 Sep 16.


The pulmonary arteries (PA) in pulmonary arterial hypertension (PAH) are constricted and remodeled;. They have suppressed apoptosis, partly attributable to suppression of the bone morphogenetic protein axis and selective downregulation of PA smooth muscle cell (PASMC) voltage-gated K+ channels, including Kv1.5. The Kv downregulation-induced increase in [K+]i, tonically inhibits caspases, further suppressing apoptosis. Mitochondria control apoptosis and produce activated oxygen species like H2O2, which regulate vascular tone by activating K+ channels, but their role in PAH is unknown. We show that dichloroacetate (DCA), a metabolic modulator that increases mitochondrial oxidative phosphorylation, prevents and reverses established monocrotaline-induced PAH (MCT-PAH), significantly improving mortality. Compared with MCT-PAH, DCA-treated rats (80 mg/kg per day in drinking water on day 14 after MCT, studied on day 21) have decreased pulmonary, but not systemic, vascular resistance (63% decrease, P<0.002), PA medial thickness (28% decrease, P<0.0001), and right ventricular hypertrophy (34% decrease, P<0.001). DCA is similarly effective when given at day 1 or day 21 after MCT (studied day 28) but has no effect on normal rats. DCA depolarizes MCT-PAH PASMC mitochondria and causes release of H2O2 and cytochrome c, inducing a 10-fold increase in apoptosis within the PA media (TUNEL and caspase 3 activity) and decreasing proliferation (proliferating-cell nuclear antigen and BrdU assays). Immunoblots, immunohistochemistry, laser-captured microdissection-quantitative reverse-transcription polymerase chain reaction and patch-clamping show that DCA reverses the Kv1.5 downregulation in resistance PAs. In summary, DCA reverses PA remodeling by increasing the mitochondria-dependent apoptosis/proliferation ratio and upregulating Kv1.5 in the media. We identify mitochondria-dependent apoptosis as a potential target for therapy and DCA as an effective and selective treatment for PAH.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Cell Division / drug effects
  • Cells, Cultured / drug effects
  • Dichloroacetic Acid / pharmacology
  • Dichloroacetic Acid / therapeutic use*
  • Drug Evaluation, Preclinical
  • Gene Expression Regulation / drug effects
  • Heart Failure / etiology
  • Heart Failure / prevention & control
  • Hemodynamics / drug effects
  • Hypertension, Pulmonary / chemically induced
  • Hypertension, Pulmonary / complications
  • Hypertension, Pulmonary / drug therapy*
  • Hypertension, Pulmonary / pathology
  • Hypertrophy, Right Ventricular / etiology
  • Hypertrophy, Right Ventricular / pathology
  • Kv1.5 Potassium Channel
  • Mitochondria / drug effects
  • Monocrotaline / toxicity
  • Muscle, Smooth, Vascular / drug effects*
  • Muscle, Smooth, Vascular / pathology
  • Myocytes, Smooth Muscle / drug effects*
  • Myocytes, Smooth Muscle / pathology
  • Organ Specificity
  • Oxidative Phosphorylation / drug effects
  • Potassium Channels, Voltage-Gated / genetics
  • Potassium Channels, Voltage-Gated / metabolism
  • Pulmonary Artery / cytology
  • Pulmonary Artery / drug effects*
  • Rats
  • Shab Potassium Channels
  • Vascular Resistance / drug effects


  • Kcna5 protein, rat
  • Kv1.5 Potassium Channel
  • Potassium Channels, Voltage-Gated
  • Shab Potassium Channels
  • Monocrotaline
  • Dichloroacetic Acid