Immunohistochemical study of p47Phox and gp91Phox distributions in rat brain.

NADPH oxidase is multi-component enzyme, which comprises the cytosolic proteins p40Phox, p47Phox, and p67Phox and the two membrane proteins, gp91Phox and p22Phox, and which is well characterized in phagocytic cells. NADPH oxidase is a primary source of reactive oxygen species (ROS), and recent studies indicate that free radicals and ROS might be causative factors of several brain degenerative diseases and dysfunctions. However, though previous studies have shown the presence of NADPH oxidase subunits in cell culture and mouse brain, they have not provided detailed high power resolution data. Therefore, we investigated the distributions of the p47Phox and gp91Phox subunits in rat brain using immunohistochemical approach. Cortex, hippocampus, and Purkinje cells of cerebellum were prominently stained by p47Phox and gp91Phox antibodies. As compared with the distributions of p47Phox, gp91Phox in mouse, some differences in the rat brain were observed in the hippocampus, thalamus, amygdala, reticular nucleus, and basal ganglia. Additionally, at the cellular level, most p47Phox immunoreactivity was largely confined to cell bodies and proximal portions of the dendritic tree. Taken together, the widespread observed distributions of p47Phox and gp91Phox subunits indicate that they are probably needed to maintain normal brain function.