Mechanism of hepatic fatty acid uptake.

In recent years a new concept of the mechanism of hepatic fatty acid uptake has been described. It was shown that this major class of energy yielding substrates enters hepatocytes by a carrier-mediated uptake system. After the dissociation of the fatty acid-albumin complex at the sinusoidal liver cell plasma membrane, fatty acid binds with high affinity to a specific, newly identified, 40 kDa membrane fatty acid binding protein (MFABP). This protein functions as transmembrane transporter for long chain fatty acids. Hepatocellular uptake of fatty acids was shown to be sodium-dependent and electrogenic, compatible with a Na+-fatty acid cotransport system.