Abstract
In recent years, liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been used in the research on advanced glycation end-products (AGEs), enabling the measurement of several types of AGEs. However, there still remain many unknowns regarding how AGE accumulate in tissues during aging and age-related diseases, and the relationship between each biological tissue and AGE accumulation. We have established a method for the determination of AGEs in various tissues using mice as an animal model and have quantified AGEs in various soft tissues, turning out to be difficult to quantify AGEs in bone tissue, which is a hard tissue, unlike soft tissue processed easily. In this study, we attempted to quantify AGEs in mouse femur using LC-MS/MS. As a result, Nε-(carboxymethyl)lysine (CML) and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were clearly detected in mouse femur, and the amount of CML in femur was significantly higher than that in the crystalline lens. These results confirm that AGE content is high in tissues such as bone, where metabolism and inflammatory reactions occur actively through the action of osteoblasts and osteoclasts. The fact that AGEs in hard tissues as well as soft tissues of mice can now be quantified using LC-MS/MS is expected to make it more effortless to study AGEs in rodents in the future.