Quantification of Carnitine and Acylcarnitines in Biological Matrices by HPLC Electrospray Ionization– Mass Spectrometry

Minkler, Paul E.; Stoll, Maria S.K.; Ingalls, Stephen T.; Yang, Shuming; Kerner, János; Hoppel, Charles L.

doi:10.1373/clinchem.2007.099226

Cited by 73 publications

(52 citation statements)

References 29 publications

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“…In comparison to carnitine, skeletal muscle concentrations of acetylcarnitine and propionylcarnitine are much lower under resting conditions. Similar to plasma, the acetylcarnitine concentration in skeletal muscle is in the range of 20% of the free carnitine concentrations (Friolet et al, 1994;Minkler et al, 2008), whereas, to the best of our knowledge, skeletal muscle propionylcarnitine concentrations have so far not been reported. A favorable gradient between plasma and skeletal muscle after supplementation could therefore facilitate transport of the amphiphilic acetyl-and propionylcarnitine into skeletal muscle by passive diffusion.…”

Section: Introductionmentioning

confidence: 64%

Effect of carnitine, acetyl-, and propionylcarnitine supplementation on the body carnitine pool, skeletal muscle composition, and physical performance in mice

et al. 2013

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Reprint requestUnfortunately, due to copyright-relatedt issues, we are not able to post the post-print pdf version of our manuscript -in some cases, not even any version of our manuscript. Thus, if you would like to request a post-production, publisher pdf reprint, please click send an email with the request to christoph-dot-handschin_at_unibas-dot-ch (see http://www.biozentrum.unibas.ch/handschin).Information about the Open Access policy of different publishers/journals can be found on the SHERPA/ROMEO webpage: http://www.sherpa.ac.uk/romeo/ Reprint AnfragenAufgrund fehlender Copyright-Rechte ist es leider nicht möglich, dieses Manuskript in der finalen Version, z.T. sogar in irgendeiner Form frei zugänglich zu machen. Anfragen für Reprints per Email an christoph-dot-handschin_at_unibas-dot-ch (s. http://www.biozentrum.unibas.ch/handschin). AbstractCarnitine has key functions in energy metabolism. In most studies in animals or humans, carnitine supplementation did not influence muscle composition and function, but the effects of the carnitine esters acetylcarnitine or propionylcarnitine are not well characterized. We therefore investigated the influence of carnitine, acetylcarnitine and propionylcarnitine on body carnitine homeostasis, energy metabolism and physical performance in mice. Animals were orally supplemented with approximately 2 mmol/kg/d carnitine, acetylcarnitine or propionylcarnitine for four weeks, before being subjected to exhaustive exercise and analysis of skeletal muscle energy metabolism and morphology.In supplemented groups, the total plasma and urine carnitine concentrations were significantly higher than in the control group, whereas the skeletal muscle carnitine content remained unchanged. The bioavailability of supplemented carnitine or acylcarnitines was in the range of 20 to 23% as determined by urinary excretion of total carnitine. The supplemented acylcarnitines were hydrolyzed in the intestine and in the liver before reaching the systemic circulation. Skeletal muscle morphology including fiber type composition was not affected by treatment with carnitine or acylcarnitines. Oxygen consumption by muscle fibers obtained from soleus or gastrocnemius was not different between the groups. The supplementation of carnitine or acylcarnitines had no significant impact on the running capacity and on key substrates of skeletal muscle energy metabolism such as glycogen, ATP, phosphocreatine or creatine.In conclusion, oral supplementation of carnitine, acetylcarnitine or propionylcarnitine is associated with increased plasma concentrations of total carnitine and increased urinary excretion of carnitine, but does not affect the skeletal muscle carnitine content. Accordingly, physical performance, skeletal muscle energy metabolism, and muscle fiber type composition are not affected by high oral doses of carnitine or acylcarnitines in mice.

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Section: Introductionmentioning

confidence: 64%

Effect of carnitine, acetyl-, and propionylcarnitine supplementation on the body carnitine pool, skeletal muscle composition, and physical performance in mice

et al. 2013

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“…Carnitine concentrations were determined from 100l of plasma using HPLC-MS methods as previously described (Minkler et al, 2005;Minkler et al, 2008;Adams et al, 2009). The limit of detection (LOD) for individual acylcarnitines using this method is 20nmoll .…”

Section: Acylcarnitine Profilingmentioning

confidence: 99%

Decreased expression of adipose CD36 and FATP1 are associated with increased plasma non-esterified fatty acids during prolonged fasting in northern elephant seal pups (Mirounga angustirostris)

Viscarra

Vázquez‐Medina

Rodríguez

et al. 2012

Journal of Experimental Biology

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SUMMARYThe northern elephant seal pup (Mirounga angustirostris) undergoes a 2-3month post-weaning fast, during which it depends primarily on the oxidation of fatty acids to meet its energetic demands. The concentration of non-esterified fatty acids (NEFAs) increases and is associated with the development of insulin resistance in late-fasted pups. Furthermore, plasma NEFA concentrations respond differentially to an intravenous glucose tolerance test (ivGTT) depending on fasting duration, suggesting that the effects of glucose on lipid metabolism are altered. However, elucidation of the lipolytic mechanisms including lipase activity during prolonged fasting in mammals is scarce. To assess the impact of fasting and glucose on the regulation of lipid metabolism, adipose tissue and plasma samples were collected before and after ivGTTs performed on early (2weeks, N5) and late (6-8weeks; N8) fasted pups. Glucose administration increased plasma triglycerides and NEFA concentrations in late-fasted seals, but not plasma glycerol. Fasting decreased basal adipose lipase activity by 50%. Fasting also increased plasma lipase activity twofold and decreased the expressions of CD36, FAS, FATP1 and PEPCK-C by 22-43% in adipose tissue. Plasma acylcarnitine profiling indicated that late-fasted seals display higher incomplete LCFA -oxidation. Results suggest that long-term fasting induces shifts in the regulation of lipolysis and lipid metabolism associated with the onset of insulin resistance in northern elephant seal pups. Delineation of the mechanisms responsible for this shift in regulation during fasting can contribute to a more thorough understanding of the changes in lipid metabolism associated with dyslipidemia and insulin resistance in mammals.

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“…Acylcarnitines were isolated by strong cation exchange solid phase extraction, derivatized with pentafluorophenacyl trifluoromethanesulfonate, and analyzed by UHPLC-MS/MS for content and for 13 C enrichment as described in detail earlier (18,19). Acyl-CoAs were isolated using solid-phase anion exchange columns (Supelco) as described (17).…”

Section: Methodsmentioning

confidence: 99%

“…This method of isotope deconvolution uses a comparison between a known unlabeled standard and the labeled analyte. Standard isotope abundances came from acylcarnitines and acyl-CoAs prepared along with the biological samples (18). The data are expressed as relative 13 C enrichment.…”

Section: Methodsmentioning

confidence: 99%

Fatty Acid Chain Elongation in Palmitate-perfused Working Rat Heart

Kerner

Minkler

Lesnefsky

et al. 2014

Journal of Biological Chemistry

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Background:In [16,16,16-d 3 ]palmitic acid (Mϩ3) perfused working hearts, Mϩ3 stearoylcarnitine is formed. Results: Rat hearts chain-elongate palmitate to stearate and arachidate. Furthermore, rat heart mitochondria catalyze the malonyl/acetyl-CoA-dependent chain elongation of palmitoyl-CoA. Conclusion: The two-carbon units for fatty acid chain elongation are derived from mitochondrial fatty acid ␤-oxidation. Significance: This pathway may represent the molecular basis for heart-specific fatty acid remodeling.

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Quantification of Carnitine and Acylcarnitines in Biological Matrices by HPLC Electrospray Ionization– Mass Spectrometry

Cited by 73 publications

References 29 publications

Effect of carnitine, acetyl-, and propionylcarnitine supplementation on the body carnitine pool, skeletal muscle composition, and physical performance in mice

Effect of carnitine, acetyl-, and propionylcarnitine supplementation on the body carnitine pool, skeletal muscle composition, and physical performance in mice

Decreased expression of adipose CD36 and FATP1 are associated with increased plasma non-esterified fatty acids during prolonged fasting in northern elephant seal pups (Mirounga angustirostris)

Fatty Acid Chain Elongation in Palmitate-perfused Working Rat Heart

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