Characterization of pigment epithelial cell plasma membranes from normal and dystrophic rats.

摘要: Retinal pigment epithelial cell plasma membranes were isolated from the eyes of normal and RCSdystrophic rats by binding glass microbeads to intact layer, removal bead-bound cells subsequent sucrose density gradient centrifugation. Plasma recovered gradients in identical yields characterized membrane marker enzymes, lipid analysis SDS-polyacrylamide gel electrophoresis. Membrane purification alkaline phosphodiesterase I 5'nucleotidase activities averaged 8-fold for 5.5 dystrophic rats. The ratio cholesterol per microgram protein indicated 6 7-fold both types membranes. Na + K -ATPase mutant rat was purified 5- 3.5-fold, respectively, but specific higher than normal. Subcellular organelle contamination low relatively uniform membranes, while opsin less 1%. By electrophoretic proteins similar, with 30-40 identifiable bands present each type. contain high levels cholesterol, sphingomyelin phosphatidylcholine polyunsaturated fatty acids. However, had significantly hgher docosahexaenoic acid normal, lower arachidonic acid. differences these acids membrane-bound enzymes may affect ionic balance interphotoreceptor matrix or otherwise contribute degenerative changes photoreceptors. Invest Ophthalmol Vis Sci 29:1066-1075,1988