Localisation of NADPH diaphorase activity and NOS immunoreactivity in astroglia in normal adult rat brain.

This study demonstrates the co-localisation of NADPH diaphorase activity and GFAP immunoreactivity in non-neuronal cells in weakly fixed brain sections from normal adult rats. The presence of GFAP immunoreactivity in these cells indicates that they are astroglia. In addition, cells possessing the morphological characteristics of astroglia were weakly immunoreactive for the endothelial isoform of nitric oxide synthase (eNOS)--these cells also co-localised NADPH diaphorase activity. Furthermore, cells immunoreactive for eNOS displayed GFAP immunoreactive processes. This cytochemical evidence strongly suggests that resting astroglia are potential sources of nitric oxide--a powerful modulator of cell activity.