Isolated Cardiac Muscle Performance during Fluorocarbon Immersion and Effects of Metabolic Blockade 1

Summary

The mechanical performance of isolated trabecular muscle preparations from the left ventricle of rats was evaluated while immersed in Krebs-Henseleit and fluorocar-bon solution under oxygenated conditions and during hypoxia and total metabolic blockade with combined hypoxia and iodoa-cetic acid 10^-4 M. Under oxygenated conditions, mechanical performance was relatively stable in both Krebs-Henseleit and fluorocar-bon solutions for 60 minutes. With glycolytic blockade, performance in both groups was relatively stable, although it was significantly increased in fluorocarbon solution in comparison to Krebs-Henseleit solution at 60 min (P < 0.01). With total metabolic blockade, mechanical performance fell to zero within 10 min in both Krebs-Henseleit and fluorocarbon solution. With hypoxia alone, mechanical performance declined more promptly and remained at lower levels in fluorocarbon solution than in Krebs-Henseleit solution (P < 0.001).