The effect of carnitine supplementation on carnitine balance in patients with persistent post-operative infection

Abstract The effect of L-carnitine (C) supplementation on body C balance, muscle C concentration, the leg exchange of C and some amino-acids was investigated in 8 patients with persistent post-operative infection. Before supplementation, total C concentration was 81 ± 13 μmol/l plasma (SEM) and 15.4 ± 1.5 μmol/g dry weight muscle, urinary excretion was 19 ± 4 μmol/kg × 24 h and the arterial-femoral venous concentration difference over the leg (A-FV) of free C was −2.90 ± 0.97 μmol/l, p In patients with persistent post-operative infection, muscle C concentration was normal and C was released from muscle as a consequence of muscle catabolism. The rate of C release was a major determinant of the plasma C concentration. At normal or low plasma C levels, the renal tubular reabsorption of C was a major determinant of body C balance. At elevated plasma concentrations of C, such as during C supplementation, the tubular capacity for reabsorption is exceeded and body carnitine balance is mainly dependent on the glomerular filtration.