The effect of enteral carnitine administration in humans

Open Access
Publisher Website
Google Scholar
Abstract
We previously determined that the L-carnitine uptake by human duodenal tissue occurs by both active (KT 558 µmol/L) and passive mechanisms. The effects of enteral carnitine was studied in humans. A hamburger meal (345 µmol total carnitine) induced peak jejunal fluid free (unesterified) and short-chain acylcarnitine concentrations (SCAC) of 209 and 130 µmol/ L, respectively. Plasma carnitine concentrations and the percent renal reabsorption remained unchanged. By contrast, a pharmacologic dose of free carnitine (25 298 µmol) raised peak intraluminal free and SCAC to 20 660 and 4204 µmol/L. Plasma total carnitine concentrations doubled to 93 µmol/L, and the percent renal reabsorption of free and SCAC declined to 76% and 52%, respectively. In triple-lumen perfusions, 200 µmol carnitine/L was absorbed at 484 nmol · min−1 · 30 cm−1 jejunum, a rate sufficient for prandial but not pharmacologic assimilation. Our findings indicate that absorption of physiologic and pharmacologic amounts of carnitive occurs predominantly by active transport and passive diffusion, respectively.

This publication has 23 references indexed in Scilit: