Argininic acid (CHEM003133)

Arginic acid is a uremic toxin. Uremic toxins can be subdivided into three major groups based upon their chemical and physical characteristics: 1) small, water-soluble, non-protein-bound compounds, such as urea; 2) small, lipid-soluble and/or protein-bound compounds, such as the phenols and 3) larger so-called middle-molecules, such as beta2-microglobulin. Chronic exposure of uremic toxins can lead to a number of conditions including renal damage, chronic kidney disease and cardiovascular disease. Tissue accumulation of argininic acid (AA) occurs in hyperargininemia. Hyperargininemia, an inborn error of the urea cycle, is caused by a severe deficiency of liver arginase, resulting in elevated tissue levels of arginine (Arg) and other guanidino compounds (GC). Affected patients present a neurological syndrome consisting of a variable degree of mental retardation, epilepsy and progressive spasticity whose pathophysiology is far from understood. Guanidino compounds accumulate in other pathological conditions such as uremia and epilepsy and some evidence supports the hypothesis that these compounds contribute to the neurological dysfunction characteristic of these diseases. The increase of these compounds occurs by blockage of the arginase reaction, activating secondary biochemical pathways. Thus, Arg is converted to _-keto-_-guanidinovaleric acid by transamination, and this compound forms AA by hydrogenation. (2).