In the isolated C57/BL6 mouse heart, energy was produced by oxidation of long-chain fatty acids (18%), and isoproterenol decreased de novo triglyceride synthesis while increasing fatty acid oxidation.
This study demonstrates the utility of NMR spectroscopy in quantifying myocardial substrate utilization and shows that isoproterenol shifts metabolism towards increased fatty acid oxidation and decreased de novo triglyceride synthesis.
Triglyceride turnover in the isolated C57/BL6 mouse heart was measured by dynamic 13C edit-(1)H observe NMR and the rate of fatty acid oxidation was determined by 13C NMR isotopomer analysis. In the presence of a physiological mixture of substrates, energy was produced in the citric acid cycle by oxidation of long-chain fatty acids (18%), ketones (34%), lactate (24%), pyruvate (7%), and other sources (17%). Exogenous fatty acids appeared in the triglyceride pool at 0.24 micromol/g dry wt/min, similar to the rate of oxidation of long-chain fatty acids, 0.16 micromol/g dry wt/min. Isoproterenol decreased the rate of de novo triglyceride synthesis and increased the rate of fatty acid oxidation.
Stowe et al. (Fri,) conducted a other in isolated C57/BL6 mouse heart. Isoproterenol was evaluated on Triglyceride turnover and rate of fatty acid oxidation. In the isolated C57/BL6 mouse heart, energy was produced by oxidation of long-chain fatty acids (18%), and isoproterenol decreased de novo triglyceride synthesis while increasing fatty acid oxidation.