Immunohistochemical demonstration of glutamate dehydrogenase in astrocytes

A rabbit antiserum was raised against glutamate dehydrogenase (GDH) and applied immunohistochemically to rat brain. GDH-immunoreactive grains were observed mainly in small cells throughout the brain. In most of these cells, coexistence of GDH and glial fibrillary acidic protein was shown by an immunofluorescence method. The results suggest that GDH is primarily an astrocytic enzyme. Possible roles of astrocytic GDH in glutamate and ammonia metabolism are discussed.