Plasma Amino Acid Concentration in the Hepatic Vein Compared to Peripheral Blood

The liver plays a key role in the metabolism of amino acids as it removes releases and incorporates them into different proteins and compounds. Patients with liver disease show abnormalities in the plasma amino-acid profile [1-3]. In advanced liver disease there is usually an increased concentration of the aromatic amino-acids (AAA) tyrosine, phenylalanine and tryptophan, and decreased concentration of branched-chain amino acids (BCAA) leucine, isoleucine and valine in plasma [4-12]. The methods used to investigate amino acid metabolism have varied widely i.e. basal measurements, protein challenge tests, fasting and postabsorptive period, samples obtained from peripheral or arterial blood to mention a few [3,10].