Neurochem Res. 1989 May.
Uptake of acetyl-L-carnitine in the brain.
Burlina AP, Sershen H, Debler EA, Lajtha A.
Nathan S. Kline Institute for Psychiatric Research, Center for Neurochemistry, New York, NY.

Analysis in mouse brain slices of the uptake of acetyl-L-[N-methyl-14C]carnitine with time showed it to be concentrative, and kinetic analysis gave a Km of 1.92 mM and a Vmax of 1.96 mumol/min per ml, indicating the presence of a low-affinity carrier system. The uptake was energy-requiring and sodium-dependent, being inhibited in the presence of nitrogen (absence of O2), sodium cyanide, low temperature (4 degrees C), and ouabain, and in the absence of Na+. The uptake of acetyl-L-carnitine was not strictly substrate-specific; gamma-butyrobetaine, L-carnitine, L-DABA, and GABA were potent inhibitors, hypotaurine and L-glutamate were moderate inhibitors, and glycine and beta-alanine were only weakly inhibitory. In vivo, acetyl-L-carnitine transport across the blood-brain barrier had a brain uptake index of 2.4 +/- 0.2, which was similar to that of GABA. These results indicate an affinity of acetyl-L-carnitine to the GABA transport system.

Categories: 1989, Carnitine, Acetyl-l-carnitine, Brain, Blood-brain barrier, Glutamate, GABA, Glycine, Alanine