Uremic toxins in chronic renal failure

The uremic syndrome is a complex mixture of organ dysfunctions, which is attributed to the retention of a myriad of compounds that under normal conditions are excreted by healthy kidneys. During recent years major steps have been taken in the area of identification and characterization of uremic retention solutes and in the knowledge of their pathophysiological importance; however, our knowledge remains far from complete. In the present paper the general classification based on their molecular weight and on their protein-binding characteristics, with reflections on their removal, will be discussed. In addition, current knowledge about the main uremic retention products and their clinical and biological effects will be reviewed in detail.