Evaluation of Fatty Acid and Glucose Metabolism in Myocardium of Heart Using Dual Radiopharmaceutical Approach

Abstract

Understanding the metabolic consequences of Heart Failure (HF) is important in evaluating potential mechanism for disease progression in the heart, based on that we investigated whether changes of myocardial uptake of fatty acid and glucose tracer after induction of heart failure in various conditions in rats heart were closely related to alterations in myocardial fatty acid and glucose metabolism. The dual radiopharmaceuticals, 31I- 15-(p-iodophenyl)-9-methylpentadecanoic acid (9MPA) and 14C- 2-deoxy-D-[1-14C] glucose (2DG) used to evaluate the changes of fatty acid and glucose metabolism of myocardium respectivelyin normal and HF stages with time.The myocardial uptake of whole heart and left ventricular were measured by Differential Absorption Ratio (DAR) and dual-tracer autoradiography in normal, acute and Chronic Heart Failure (CHF) at 5, 10, 30 and 60 minutes. Accumulation properties were compared with normal, HF stages and among HF stages using independent two sample t- test. Accumulation of 132 I 9MPA in acute and CHF stages at 5, 30 minutes, normal and CHF stages at 30 minutes did not show any significant difference ( p>0.05). in normal stage accumulation of 14 C-2DG with CHF and acute stages at 30 and 60 minutes respectively did not show any significant different ( p>0.05). In acute condition left ventricular myocardial accumulation of 131I-9MPA was high and it deviated significantly from other part of myocardium in specific acute stage of heart. Metabolic functions of the heart vary with time in normal and HF stages. Mainly acute stage shows significant changes of metabolic function in whole and left ventricular myocardium. When the metabolic function of heart in normal and HF stages are compared, they do not differ significantly with time.