Palmitate oxidation in human muscle: Comparison to CPT and carnitine

The evaluation of palmitate oxidation in muscle tissue may be a useful screening test for detecting defects in fatty acid metabolism in human neuromuscular disease. If the test is to be useful, it is necessary to obtain data on a wide variety of muscle illnesses for comparative purposes. We report our experience with palmitate oxidation, muscle carnitine, and carnitine palmityl transferase (CPT) activity in 148 muscle biopsies from a variety of illnesses. The efficacy of using total protein, citrate synthase, and (1‐¹⁴C) pyruvate oxidation as internal references was investigated. Palmitate oxidation was significantly less than normal (P ≤ 0.01) in Duchenne muscular dystrophy, congenital nonprogressive myopathy, congenital muscular dystrophy, malignant hyperpyrexia, and denervation, depending on the internal reference used. Muscle carnitine levels followed a similar pattern, however, CPT activity did not. The possibility of these findings being secondary to inactivity is discussed.