Tissue distribution of endogenously formed and orally administered low molecular mass advanced glycation end-products in rats.

This study quantified the tissue distribution in rats of four exogenously administered and endogenously formed low molecular mass (LMM) AGEs, including glycolic acid-lysine-amide (GALA), N-ε-(carboxyethyl)lysine (CEL), N-ε-(carboxymethyl)lysine (CML) and pyrraline. Two hours after gavage administration of a mixture of the AGEs at 10 mg/kg body weight each, the free exogenously administered AGEs were detectable in the tissues, with the highest concentration in the kidneys, where levels of the exogenous AGEs were substantially higher than those of the endogenously formed counterparts. Endogenous and exogenous AGEs showed tissue specific patterns pointing at tissue specific differences in their formation, absorption and/or clearance and variable contributions of exogenous AGEs to the overall exposome. The results confirmed the bioavailability of free AGEs in the body and revealed distinct tissue biodistribution and elimination patterns among the four AGEs, showing that especially in the kidney oral exposure at estimated daily intakes may add to the exposome.