Expression of mitochondrial regulatory genes parallels respiratory capacity and contractile function in a rat model of hypoxia-induced right ventricular hypertrophy

• Published in: Molecular and Cellular Biochemistry
• Main Authors: Zungu M., Young M.E., Stanley W.C., Essop M.F.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2008
• Subjects: animal cell; animal experiment; animal model; article; controlled study; gene expression; heart contraction; heart function; heart left ventricle; heart right ventricle; heart right ventricle hypertrophy; heart weight; hypoxia; male; mitochondrial respiration; mitochondrion; nonhuman; oxygen consumption; rat; regulator gene; respiration control; systolic blood pressure; upregulation; Wistar rat; Animals; Anoxia; Cell Respiration; Disease Models; Animal; Gene Expression Regulation; Genes; Regulator; Heart Function Tests; Hemodynamics; Hypertrophy; Right Ventricular; Mitochondria; Myocardial Contraction; Rats; Wistar; RNA; Messenger; Rattus; Rattus norvegicus; Rattus rattus
• Online Access: http://hdl.handle.net/10019.1/11476; https://doi.org/10.1007/s11010-008-9867-5

Chronic hypobaric hypoxia (CHH) increases load on the right ventricle (RV) resulting in RV hypertrophy. We hypothesized that CHH elicits distinct responses, i.e., the hypertrophied RV, unlike the left ventricle (LV), displaying enhanced mitochondrial respiratory and contractile function. Wistar rats were exposed to 4 weeks CHH (11% O2) versus normoxic controls. RV/body weight ratio increased (P < 0.001 vs. control) while RV systolic and developed pressures were higher. However, LV systolic and developed pressures were significantly reduced. Mitochondrial O2 consumption was sustained in the hypertrophied RV, ADP/O increased (P < 0.01 vs. control) and proton leak significantly decreased. Conversely, LV mitochondrial O2 consumption was attenuated (P < 0.05 vs. control) and proton leak significantly increased. In parallel, expression of mitochondrial regulators was upregulated in the hypertrophied RV but not the LV. Our data show that the hypertrophied RV induces expression of mitochondrial regulatory genes linking respiratory capacity and enhanced efficiency to sustained contractile function. © Springer Science+Business Media, LLC. 2008. Article