ADVANCED GLYCOSYLATION END-PRODUCTS IN ADRENAL LIPOFUSCIN

The present study examined the presence of advanced glycosylation end products (AGEs) in lipofuscin present in the brain and adrenal gland o f aging rats by immunohistochemistry using antibodies raised against A GEs. Lipofuscin identified as yellow to brown granules emitting bright yellow to orange autofluorescence with ultraviolet light were detecte d in cortical neurons, cerebellar Purkinje cells, and adrenal cells in the inner part of the zona reticularis. However, none of the antibodi es visualized lipofuscin in these areas. The outer part of the zona re ticularis contained yellow granules emitting a faint orange autofluore scence. These granules were immunostained by an antibody that reacted with AGEs structures unrelated to the carboxymethyllysine moiety. Newl y formed adrenal cortical cells are thought to migrate from the outer layer to the inner layer of the zona reticularis. Therefore, our resul ts suggest that glycosylation-related processes are involved in lipofu scinogenesis, at least in its early stage, in the adrenal zona reticul aris.