Expression of PPAR α and M-CPT-ImRNA in Cardiac Hypertrophy
HU Qin, LI Long gui (Cardiology center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China)
Objective To study the expression of PPAR α and M CPT I mRNA in cardiac hypertrophy and the regulation effect of PPAR α on mitochondrial fatty acid uptake. Methods Using a model of cardiac hypertrophy induced by coarctation of abdominal aorta(CAA) in male Wistar rats, hemodynamics, ventricular remodeling parameters, free fatty acid in blood serum and cardiac myocyte and expression of PPAR α and M CPT I mRNA were investigated 2, 4, 8, 16 weeks after operation and sham operation. Results Cardiac PPAR α and M CPT I gene expression were decreased, meanwhile the accumulation of free fatty acid and a reduction in uptake of fatty acid in myocardium were manifested in the development of cardiac hypertrophy. Conclusion The metabolic substrate in hypertrophic myocardium underwent substantial changes. Fatty acid oxidation appears not to be a major substrate of energy metabolism in cardiac hypertrophy. PPAR α is deactivated at transcriptional level and plays a key role on mitochondrial import of fatty acids in myocardial, leading to diminish in myocardial lipid and energy homeostasis.