Myocardial Metabolism and Performance during Sodium Salicylate Infusion in Dogs

Abstract

The effect of sodium salicylate on net myocardial free fatty acid (FFA) uptake, myocardial oxygen consumption (MVO₂), and the mechanical activity of the heart was studied in eight intact, anesthetized dogs. Sodium salicylate was given intravenously under basal conditions and during isoproterenol-stimulated lipolysis. Under basal conditions, sodium salicylate significantly reduced arterial FFA concentration, but did not influence net myocardial uptake of FFA, and MVO₂ was unchanged. During isoproterenol infusion sodium salicylate reduced arterial FFA concentration by 28% (P0.01) and significantly reduced net myocardial uptake of FFA from 44.5 ±9.0 (mean±S.E.M.) to 22.3 ±2.1 μmol/min-100 g tissue (P<0.05) and MVO₂ from 20.3±2.2 to 16.0±1.9 ml/min-100 g tissue (P<0.05). The reduction in MVO₂ could not be explained by reduced mechanical activity of the heart. Most probably the mechanism for the reduction in MVO₂ effected by sodium salicylate during isoproterenol infusion was mediated by reduced myocardial FFA consumption.

Key Words:

• Free fatty acids
• glucose
• glycerol
• isoproterenol
• lipolysis
• myocardial blood flow
• myocardial oxygen consumption
• myocardial performance
• sodium salicylate