Impact of 1 wk of diabetes on the regulation of myocardial carbohydrate and fatty acid oxidation.

Academic Article

Abstract

  • The aim of this study was to investigate the effect of increasing exogenous palmitate concentration on carbohydrate and palmitate oxidation in hearts from control and 1-wk diabetic rats. Hearts were perfused with glucose, [3-(13)C]lactate, and [U-(13)C]palmitate. Substrate oxidation rates were determined by combining (13)C-NMR glutamate isotopomer analysis of tissue extracts with measurements of oxygen consumption. Carbohydrate oxidation was markedly depressed after diabetes in the presence of low (0.1 mM) but not high (1.0 mM) palmitate concentration. Increasing exogenous palmitate concentration 10-fold resulted in a 7-fold increase in the contribution of palmitate to energy production in controls but only a 30% increase in the diabetic group. Consequently, at 0.1 mM palmitate, the rate of fatty acid oxidation was higher in the diabetic group than in controls; however, at 1.0 mM fatty acid oxidation, it was significantly depressed. Therefore, after 1 wk of diabetes, the major differences in carbohydrate and fatty acid metabolism occur primarily at low rather than high exogenous palmitate concentration.
  • Published In

    Keywords

  • Animals, Carbohydrate Metabolism, Diabetes Mellitus, Experimental, Energy Metabolism, Fatty Acids, Heart, In Vitro Techniques, Magnetic Resonance Spectroscopy, Male, Myocardium, Osmolar Concentration, Oxidation-Reduction, Palmitates, Rats, Rats, Sprague-Dawley, Triglycerides
  • Digital Object Identifier (doi)

    Author List

  • Chatham JC; Gao ZP; Forder JR
  • Start Page

  • E342
  • End Page

  • E351
  • Volume

  • 277
  • Issue

  • 2