Biochem Biophys Res Commun. 1997 Feb 13.
High uptake of [2-11C]acetyl-L-carnitine into the brain: a PET study.
Kuratsune H, Watanabe Y, Yamaguti K, Jacobsson G, Takahashi M, Machii T, Onoe H, Onoe K, Matsumura K, Valind S, Kitani T, Langstrom B.
Subfemtomole Biorecognition Project, Japan Science and Technology Corporation, Osaka, Japan.
[ PubMed ]

Abstract: The brain uptake of acetylcarnitine was investigated in rhesus monkeys using different position labeled acetyl-L-carnitine and related molecules with 11C by positron emission tomography. The uptake values of radio-labeled acetylcarnitine into the brain were quite different depending on the labeling positions of 11C. That is, the uptake values of L-[methyl-11C]carnitine and acetyl-L-[methyl-11C]carnitine were almost the same and extremely low, while the uptake of [1-11C]-acetyl-L-carnitine was slightly higher. The uptake value of [2-11C]acetyl-L-carnitine was by far the highest among the 11C-labeled acetyl-L-carnitine and L-carnitine. The uptake of [2-11C]acetyl-L-carnitine into the brain was suppressed by the intravenous administration of glucose. These results suggest that endogenous serum acetyl-L-carnitine has some roles on conveying an acetyl moiety into the brain especially under an energy crisis, and that an unknown metabolic pathway of [2-11C]acetyl moiety might be rather active in the brain.