DIFFERENTIAL EXPRESSION OF GLIAL FIBRILLARY ACIDIC PROTEIN (GFAP) IN THE RETINAE AND VISUAL CORTICES OF RATS WITH EXPERIMENTAL RENAL-HYPERTENSION

To examine the expression of the GFAP protein in the retina and visual cortex under normal and pathological conditions, hypertension was ind uced in adult male Sprague-Dawley rats by applying silver clips onto r enal arteries and the change in GFAP expression was followed by Wester n blotting and immunocytochemical staining. One week after operation w hen the induced hypertension was at the initial stage, GFAP expression in the retina was reduced to half of the sham control. By 4 weeks, wh en consistent hypertension was developed, a further decrease in the le vel of GFAP expression in the retina to one third of the sham control was observed. Immunocytochemical staining showed that the number of GF AP-positive cells in the nerve fiber layer of the retina of the hypert ensive rat was reduced to less than one third of the sham control. How ever, similar changes in GFAP expression in the visual cortex of hyper tensive rats were not observed, This study represents the first report to date on GEAR expression in the retina and visual coder and include s discussion of the possible mechanisms through which GFAP expression is mediated.