Pentosidine

Pentosidine is a biomarker for advanced glycation endproducts, or AGE. It is studied because it is a well-characterized and easily-detected member of this large class of compounds.

Background
AGE are a large class of biochemicals formed continuously in the body under normal conditions, but more so under a variety of stressors, especially oxidative stress and hyperglycemia. They both serve as markers of stress and act as toxins themselves. Pentosidine is a typical member of this class, except that it fluoresces. This allows it to be easily measured and visualized. As it is well characterized, it is studied to give insight to the biochemistry of the larger class of AGE compounds.

Biochemistry
Pentosidine is a pentose-derived fluorescent cross-link formed between arginine and lysine residues in collagen. It is formed as a reaction of the amino acids with the Maillard reaction products of ribose.

Although it is present in only trace concentrations in tissue proteins, it is a useful biomarker for assessing cumulative damage to proteins&mdash;advanced glycation endproducts&mdash;by non-enzymatic browning reactions with carbohydrates.

Physiology
In vivo, AGE forms pentosidine through sugar fragmentation. In patients with Diabetes mellitus type 2, pentosidine correlates with the presence and severity of diabetic complications.