Slow Decay of Acetyl-Carnitine in Skeletal Muscle After Exercise

Jimin Ren¹, Ivan Dimitrov², Dean Sherry¹, Craig Malloy¹

Rapid interconversion of acetyl-CoA with acetyl-carnitine buffers acetyl-CoA when the rate of generation of acetyl-CoA exceeds the rate of oxidation. Exercise has been shown to increase acetyl-carnitine little is known about the kinetics of recovery. Healthy subjects were studied by single-voxel spectra acquired from soleus muscle using a 7T scanner. Standard calf flexion / extension exercise was performed outside the magnet. The resonance areas of carnitine, creatine and taurine did not change during recovery. Acetyl-carnitine decayed slowly with a rate constant of 19.3 +/- 2.4 min. The acetyl-carnitine/carnitine ratio remains high for a prolonged period after exercise.