Taurine, serum levels

Maes M, Verkerk R, Vandoolaeghe E, Lin A, Scharpe S (1998) Serum levels of excitatory amino acids, serine, glycine, histidine, threonine, taurine, alanine and arginine in treatment-resistant depression Modulation by treatment with antidepressants and prediction of clinical responsivity. Acta Psychiatr Scand 97 302-308. 

Interestingly, the number of examples of toxicity biomarkers discovered using nuclear magnetic resonance (NMR)-based and MS-based metabonomics is quite impressive. In metabonomics studies in which a severe toxicity is observed, almost always the relative urinary concentrations of Krebs cycle intermediates are decreased and a concomitant decrease in urinary levels of hippuric acid is observed. These compounds have been proposed to be nonspecific markers of toxicity as they reflect a combination of complex changes in an organism [11,48-51], Taurine has been known to be a specific marker for liver toxicity as its urinary levels are typically increased with necrosis and fatty liver. Several bile acids in the serum such as cholic, glycolic, and taurocholic acids have also been demonstrated to be sensitive markers of liver dysfunction [50], In the literature, there are a few preclinical and clinical examples of... 

Recently, it was found that unconjugated bile acids (CA, CDCA, and DCA) are present at high (nmol/g tissue) levels in the rat brain cytoplasmic fraction, but their functions in the central nervous system are unclear. To clarify this point, a profile analysis of file rat serum bile acids (eight common bile acids and their glycine and taurine conjugates) has been demonstrated. ... 

Certain amino acids are maintained at higher concentration in blood cells compared to plasma. This is the case for taurine, glutamate, aspartate, glutathione and for argininosuccinate, when present. Thus, hemolysis often increases the levels of these amino acids in plasma or serum. Hemolysis also releases the enzyme arginase, which hydrolyzes arginine to ornithine. 

A.S. Truswell, S. McVeigh, W.D. Mitchell, and B. Bronte-Stewart, Effect in man of feeding taurine on bile acid conjugation and serum cholesterol levels, J. Atherosclerosis Res. 5s526 (1965). 

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