Immunohistochemical detection of advanced glycation end products in human bladder with specific monoclonal antibody

Objective: To investigate the accumulation of advanced glycation end products (AGE) in human bladder. Methods: Human bladder specimens were obtained from nine patients during radical cystectomy. Frozen sections were immunohistochemically analyzed by three different monoclonal anti-AGE antibodies such as anti-N(epsilon)-(carboxymethyl)lysine (CML), anti-imidazolone and anti-pentosidine antibodies. Bladder sections were stained with these antibodies by indirect immunoperoxidase methods. Double immunohistochemical staining with one of the anti-AGE antibodies or an anti-human macrophage antibody was also carried out. Results: We demonstrated that CML and pentosidine were accumulated in human bladder extracellularly as well as intracellularly, whereas any accumulation of imidazolone was not observed. Double immunohistochemical staining indicated that AGE-accumulated cells in human bladder were derived from macrophages. Conclusions: The present study demonstrated that AGE-structures such as CML and pentosidine are accumulated extracellularly in human bladder, and were endocytosed by tissue macrophages.