Free Carnitine (free + carnitine)

Distribution by Scientific Domains


Selected Abstracts


Effects of Valproate on Acylcarnitines in Children with Epilepsy Using ESI-MS/MS

EPILEPSIA, Issue 1 2007
Tamara Werner
Summary:,Purpose: To determine the influence of valproate (VPA) treatment on acylcarnitines in children with epilepsy. Methods: Determination of acylcarnitines (including free carnitine and acylcarnitines from C2 to C18) in dried blood spot specimens using tandem-mass spectrometry. Longitudinal study of changes in acylcarnitines in children under VPA treatment without pretreatment (group 1) or with pretreatment with other antiepileptic drugs (group 2) before the start of VPA treatment at an early and a late treatment interval (12,66, 90,260 days after the beginning of treatment, respectively). Cross-sectional comparison of these two VPA groups and of a group receiving carbamazepine monotherapy (group 3) with controls. Results: Acylcarnitines in epileptic patients before VPA therapy did not differ from control values. In group 1, decreases of C0 (,26%), C2 (,12%), C16 (,31%), C18 (,41%), Ctotal (,10%), increases of C5OH (+31%), C8 (+33%) in the early treatment interval, and decreases of C16 (,21%), C18 (,42%), and increases of C2 (+26%), C5OH (+44%) in the late treatment interval were significant. In group 2, both in the longitudinal and the cross-sectional study, only a decrease of C18 (,41%, ,43%, respectively) in the late treatment interval was found. In group 3, no significant changes have been observed. Conclusions: We could prove changes in acylcarnitine subspecies, which were associated with VPA treatment in children with epilepsy. The treatment interval with the most marked changes coincides with the interval of highest risk for VPA-induced hepatotoxicity. The observed specific acylcarnitine pattern might point to the impaired intermediary metabolism that is responsible for VPA-induced hepatotoxicity. [source]


Defective hepatic mitochondrial respiratory chain in patients with nonalcoholic steatohepatitis

HEPATOLOGY, Issue 4 2003
M.D., Mercedes Pérez-Carreras Ph.D.
Mitochondrial dysfunction might play a central role in the pathogenesis of nonalcoholic steatohepatits (NASH). The aims of this study were to evaluate whether free fatty acid (FFA) transport into the mitochondria or the activity of mitochondria respiratory chain (MRC) complexes are impaired in NASH. In patients with NASH and control subjects, we measured free carnitine, short-chain acylcarnitine (SCAC) and long-chain acylcarnitine (LCAC) esters, carnitine palmitoyltransferase (CPT) activity, and MRC enzyme activity in liver tissue as well as serum concentration of tumor necrosis factor , (TNF-,), homeostatic metabolic assessment of insulin resistance (HOMAIR), and body mass index (BMI). In patients with NASH, the LCAC/free carnitine ratio was significantly increased and the SCAC/free carnitine ratio was decreased. In patients with NASH, the activity of the MRC complexes was decreased to 63% ± 20% (complex I), 58.5% ± 16.7% (complex II), 70.6% ± 10.3% (complex III), 62.5% ± 13% (complex IV), and 42.4% ± 9.1% (adenosine triphosphate synthase) of the corresponding control values. Activity of these complexes correlated significantly with serum TNF-, and HOMAIR. Serum TNF-, (36.3 ± 23.1 pg/mL), HOMAIR (4.5 ± 2.38), and BMI (29.9 ± 3.5 kg/m2) values were significantly increased in patients with NASH. In conclusion, activities of MRC complexes were decreased in liver tissue of patients with NASH. This dysfunction correlated with serum TNF-,, insulin resistance, and BMI values. (Hepatology 2003;38:999,1007). [source]


Effect of hemodialysis on carnitine levels in children with chronic renal failure

PEDIATRICS INTERNATIONAL, Issue 1 2002
Sevgi Mir
Abstract Background:,Impaired structural and metabolic integrity of the kidney in chronic renal failure (CRF) effects carnitine metabolism by means of many factors. Depletion due to hemodialysis (HD) is one of the major concerns. The aim of the study was to investigate the effects of chronic renal failure and HD on plasma free carnitine (FC) concentrations in children. Methods:,Plasma FC concentrations were measured in age-matched 14 undialyzed patients, 20 dialyzed patients and 12 healthy children. In the HD group, measurements were done pre- and postdialysis and an hour after ceasing HD. None of the children have been receiving exogenous l -carnitine replacement. Results:,Plasma FC concentrations on either HD or conservative treatment were found to be decreased as compared to the healthy subjects (P < 0.001 and P = 0.001, respectively). The patients on HD had lower levels of plasma FC at the predialysis period than those on conservative treatment (P = 0.01). The FC levels significantly dropped at the postdialysis period as compared to those at the predialysis period (P < 0.001), but recovered at 1 h after ceasing HD. The mean duration of HD did not correlate with plasma FC levels at predialysis period. Conclusions:,Children with CRF, either dialyzed or undialyzed, have decreased plasma FC levels. Hemo­dialysis treatment significantly depletes plasma FC concentrations during the procedure, but predialysis levels are reached 1 hr after ceasing HD. [source]


Metabolic effects in neonates receiving intravenous medium-chain triglycerides

ACTA PAEDIATRICA, Issue 2 2002
G Angsten
The effects of two lipid emulsions, one with 50% each of medium-chain and long-chain triglycerides, and a long-chain triglycerides lipid emulsion as a control, were evaluated for lipid and carnitine metabolism and respiratory quotient when given to neonates after major surgery during a short period of total parenteral nutrition. Each group included 10 neonates, and all tolerated the total parenteral nutrition well. The relative contents of linoleic acid and ,-linolenic acid increased in all lipid esters in plasma and adipose tissue in both groups, indicating that the content of these fatty acids is sufficient even in the medium-chain triglycerides emulsion. The serum concentration of ketones was within normal limits. Free fatty acids in plasma did not increase in either group. The total plasma carnitine concentration decreased in both groups but the distribution of free carnitine and acylcarnitine did not change. The total muscle carnitine did not change significantly but the ratio of acylcarnitine to free carnitine tended to increase in muscle in the treatment group, probably an effect of the medium-chain triglyceride supplementation. Conclusions: The two groups displayed the same fatty acid pattern in plasma and adipose tissue and the same respiratory quotient during the treatment period. Regarding carnitine status, essentially the same changes were seen in the two groups. However, discrete changes were seen in muscle tissue in the treatment group. [source]