Distinct cellular and regional localization of immunoreactive protein kinase C in rat brain

Monoclonal antibodies raised against highly purified protein kinase C were used to localize protein kinase C in the rat brain. Using various monoclonal antibodies, at least three distinct antibody-staining patterns were found. One monoclonal antibody exclusively labeled astroglial elements, including astrocytes, tanycytes, and cerebellar radial glia. Another monoclonal antibody exclusively labeled neural cells, including cortical and hippocampal pyramidal dendrites and Purkinje cells of the cerebellum. A third monoclonal antibody (which inhibited protein kinase C activity) intensely stained more limited brain regions, particularly thalamic neurons, and also stained astroglial structures in brain, spinal cord, and cerebellum. The possibility that the three staining patterns reflect the differential regional and cellular localization of related, but distinct, enzymes of protein kinase C is discussed.