CONNEXIN-43 AND THE GLUCOSE-TRANSPORTER, GLUT1, IN THE CILIARY BODY OF THE RAT

To investigate the relationship between the gap junction protein conne xin 43 and the glucose transporter GLUT1, their localization was visua lized by double-immunofluorescence microscopy using frozen sections as well as immunogold staining of ultrathin frozen sections. In pigmente d epithelial cells, most of the GLUT1 was localized along the plasma m embrane facing the blood vessels, whereas in non-pigmented epithelial cells, it was present along the plasma membrane facing the aqueous hum or. Connexin 43 was abundant in the ciliary body and localized mainly in the gap junctions connecting the pigmented and non-pigmented epithe lial cells. Localization of GLUT1 and connexin 43 in the blood-aqueous barrier suggests that GLUT1, connexin 43, and GLUT1 disposed in this order could be a machinery responsible for the transport of glucose ac ross the blood-aqueous barrier.