Dystrophin and dystrophin-related protein in the brains of normal and mdx mice.

To clarify the localization and characterization of dystrophin and dystrophin-related protein (DRP) in the brains of normal and mdx mice, we carried out immunostaining and immunoblotting studies using four region-specific antidystrophin and anti-DRP antibodies. With immunostaining, punctate immunoreactivity of dystrophin was seen along the cell bodies and dendrites of the cerebral cortical neurons in the normal mice. By contrast, dystrophin was not detected at all in the brains of mdx mice. Immunoreactivity of DRP was observed in the vascular walls, pia mater, and choroid plexus of both normal and mdx brains, but not in the neuronal cells. The possible compensatory increase of DRP as seen in the skeletal muscles of mdx mice was not noted in the brains. The immunoblot findings were very consistent with those of immunostain. Although further studies of brain-type dystrophin are necessary, it seems unlikely that DRP participates in any physiological function of the neuronal cells.