Carnitina Levogira..la forma migliore?

[Alberto86]

Siamo sicuri che la L-Carnitina sia la forma peggiore?

leggete questi 2 studi



STUDIO 1

Free and total carnitine concentrations in pig Plasma after oral ingestion of various L-carnitine compounds.

Eder K, Felgner J, Becker K, Kluge H.

Institute of Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Emil-Abderhalden-Strasse 26, 06108 Halle/Saale, Germany.
Abstract

This study was undertaken to investigate the bioavailability of various L-carnitine esters (acetyl-L-carnitine and lauroyl-L-carnitine) and salts (L-carnitine L-tartrate, L-carnitine fumarate, L-carnitine magnesium citrate) relative to base of free L-carnitine. Six groups of five or six piglets each were administered orally a single dose of 40 mg L-carnitine equivalents/kg body weight of each of those L-carnitine compounds. A seventh group served as a control. Free and total Plasma carnitine concentrations were determined 1, 2, 3.5, 7, 24, and 32 hours after administration of the single dose. Area-under-the-curve (AUC) values were calculated to assess the bioavailability of the L-carnitine compounds. AUC values, calculated for the time interval between 0 and 32 hours, for both free and total carnitine were similar for base of free L-carnitine and the three L-carnitine salts (L-carnitine L-tartrate, L-carnitine fumarate, L-carnitine magnesium citrate) while those of the two esters (acetyl-L-carnitine, lauroyl-L-carnitine) were lower. Administration of L-carnitine L-tartrate yielded a higher Plasma free carnitine AUC value for the time interval between 0 and 3.5 hours than administration of the other compounds. The data of this study suggest that L-carnitine salts have a similar bioavailability to that of free L-carnitine while L-carnitine esters have a lower one. The study also suggests that L-carnitine L-tartrate is absorbed faster than the other L-carnitine compounds.



STUDIO 2


Clin Invest Med. 2009 Feb 1;32(1):E13-9.
Comparison of pharmacokinetics of L-carnitine, acetyl-L-carnitine and propionyl-L-carnitine after single oral administration of L-carnitine in healthy volunteers.
Cao Y, Wang YX, Liu CJ, Wang LX, Han ZW, Wang CB.
The Affiliated Hospital of Medical College, Qingdao University, Qingdao, China.
Abstract
PURPOSE: To investigate the pharmacokinetics of L-carnitine (LC) and its analogues, acetyl-L-carnitine (ALC) and propionyl-L-carnitine (PLC) in healthy volunteers after single L-carnitine administration. METHODS: Liquid L-carnitine (2.0 g) was administered orally as a single dose in 12 healthy subjects. Plasma and urine concentrations of L-carnitine, ALC and PLC were detected by HPLC. RESULTS: The maximum plasma concentration (Cmax) and area under the curve (AUC 0-infinity) of L-carnitine was 84.7+/-25.2 micromol x L(-1) x h and 2676.4+/-708.3 micromol x L(-1) x h, respectively. The elimination half-life of L-carnitine and the time required to reach the Cmax (Tmax) was 60.3+/-15.0 and 3.4+/-0.46 h, respectively. The Cmax of ALC (12.9+/-5.5 micromol x L(-1)) and PLC (5.08+/-3.08 micromol x L(-1)) was lower than L-carnitine (P < 0.01), so as the AUC 0-infinity (166.2+/-77.4 and 155.6+/-264.2 micromol x L(-1) x h, respectively, P < 0.01). The half-life of ALC (35.9+/-28.9h) and PLC (25.7+/-30.3 h) was also shorter than L-carnitine (P < 0.01). The 24h accumulated urinary excretion of L-carnitine, ALC and PLC were 613.5+/-161.7, 368.3+/-134.8 and 61.3+/-37.8 micromol, respectively. CONCLUSION: L-carnitine has a greater maximum plasma concentration than ALC and PLC. L-carnitine also has a longer half-life than ALC and PLC. These data may have important implications in the designing of dosing regimens for L-carnitine or its analogues, such as ALC or PLC.
PMID: 19178874 [PubMed - indexed for MEDLINE]