Impact of lactate in the perfusate on function and metabolic parameters of isolated working rat heart.
The goal of this study was to investigate the effect of 1 mM exogenous lactate on cardiac function, and some metabolic parameters, such as glycolysis, glucose oxidation, lactate oxidation, and fatty acid oxidation, in isolated working rat hearts. Hearts from male Sprague-Dawley rats were isolated and perfused with 5 mM glucose, 1.2 mM palmitate, and 100 microU/ml insulin with or without 1 mM lactate. The rates of glycolysis, glucose, lactate, and fatty acid oxidation were determined by supplementing the buffer with radiolabeled substrates. Cardiac function was similar between lactate+ and lactate- hearts. Glycolysis was not affected by 1 mM lactate. The addition of lactate did not alter glucose oxidation rates. Interestingly, palmitate oxidation rates almost doubled when 1 mM lactate was present in the perfusate. This study suggests that subst rate supply to the heart is crucially important when evaluating the data from metabolic studies.
Onay-Besikci
Arzu
A
Department of Pharmacology, Faculty of Pharmacy, Ankara University, Tandogan 06100, Ankara, Turkey. onay@pharmacy.ankara.edu.tr
D000105:Acetyl Coenzyme A / Q000378:metabolism; D000818:Animals; D005227:Fatty Acids / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis / Q000502:physiology; D006321:Heart / Q000502:physiology*; D019344:Lactic Acid / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D017207:Rats, Sprague-Dawley
D005227:Fatty Acids; D019344:Lactic Acid; D000105:Acetyl Coenzyme A; D005947:Glucose