Hypertension induced left ventricular hypertrophy (LVH) augments the risk of cardiovascular anomalies. Oxidative stress leads to the activation of the hypertrophic program with a metabolic switch from fatty acid to glucose oxidation. Mitochondria, the major source of free radicals, exhibit alterations in hypertensive heart diseases. Targeted antioxidants are expected to reduce mitochondrial reactive oxygen species more effectively than general antioxidants. This study was designed to assess whether mito-targeted antioxidant, MitoTempol is more effective than general oxidant, Tempol on hypertension, hypertrophy and cardiac energy metabolism. Spontaneously Hypertensive Rat were administered either Tempol (20mg/kg/day) or Mito Tempol (2mg/kg/day) orally for 30 days. Post treatment, animals were subjected to 2D-echocardiography. The Myocardial lysates were subjected to Insolution digestion followed by RPLC - LTQ-Orbitrap-MS analysis. Mid-ventricular sections were probed for markers of energy metabolism and fibrosis. The beneficial effect on cardiovascular structure and function was significantly higher for Mito Tempol. Increase in mitochondrial antioxidants and stimulation of fatty acid metabolism with significant improvement in cardiovascular function was apparent in SHR treated with Mito Tempol. The study indicates that Mito Tempol is superior to its non- targeted isoform in preventing hypertension induced LVH, and the beneficial effects on heart are possibly mediated by reversal of metabolic remodelling.
Longitudinal Evaluation of Fatty Acid Metabolism in Normal and Spontaneously Hypertensive Rat Hearts with Dynamic MicroSPECT Imaging
