GLIAL FIBRILLARY ACIDIC PROTEIN INCREASES IN MULLER CELLS AFTER RETINAL-DETACHMENT

Retinal detachment, separation of the neural retina from the regina pigment epithelium (RPE), initiates a series of changes in the eye which result in loss of vision if the retina is not rapidly reattached to the RPE. Many of the complex effects of this separation on the cell biology of the retina have yet to be determined. We report here a change in the amount and location of a specific cytoskeletal protein, glial fibrillary acidic protein (GFAP), within Muller cells after retinal detachment. Cat neural retina and RPE were separated by injecting fluid into the extracellular space between the retina and RPE. Normal retinas and retinas detached for 30 days were fixed and embedded for conventional electron microscopy or immunocytochemistry, or homogenized and processed by SDS-PAGE for immunoblot analysis with anti-GFAP. In normal retinas and in attached retinal regions of eyes with retinal detachment, GFAP was detected only in the end feet of the Mueller cells as 10 nm diameter filaments and as a diffuse component over the cytoplasm. By contrast, in regions where the retina was deteched from the RPE, GFAP was localized throughout the Mueller cells in both of these forms. Immunoblots revealed a significant increase in anti-GFAP labeling of a 51000 MW band from the detached retina.