CYSTIC-FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR IS FOUND WITHIN BRAIN VENTRICULAR EPITHELIUM AND CHOROID-PLEXUS

The cystic fibrosis gene product, cystic fibrosis transmembrane conduc tance regulator (CFTR), functions as a Cl- channel that is regulated b y cyclic AMP-dependent phosphorylation. We have investigated the expre ssion of CFTR protein in the rodent brain by both western blotting of samples prepared by microdissection and immunohistochemistry. CFTR was found to be expressed in choroid plexus and ependyma. In tissue secti ons, CFTR-like immunoreactivity was concentrated in fine puncta locali zed about 1-2 mu m from the CSF-contacting side of ependyma and choroi d plexus. CFTR in choroid plexus may play a role in the regulation of the composition of CSF by cyclic AMP-elevating agents, but the role of this chloride transporter in ependymal function remains to be determi ned.