title: Metabolic studies on retinal tissue from a donor with a dominantly inherited chorioretinal degeneration resembling sectoral retinitis pigmentosa.
abstract: Protein synthesis, glycosylation, RNA synthesis, and neurotransmitter uptake were monitored using biochemical and autoradiographic techniques following in vitro labeling of retinal tissue from a 79-year-old female with sectoral retinitis pigmentosa (RP). Comparisons were made between degenerate and non-degenerate regions of the RP retina, and normal retinal tissues from an age- and postmortem-matched donor. Autoradiographs of non-degenerate retina from the RP eye following 3H-uridine incubation revealed virtually identical silver grain density over nuclei in all retinal strata as compared to normal control retinas. In contrast, a photoreceptor-specific reduction in silver grain density in the non-degenerate RP retina was noted following 3H-leucine incubation. In the normal retina, rod photoreceptor labeling with 3H-mannose was always greater than cone photoreceptor labeling. This pattern of incorporation was reversed in the non-degenerate region of the RP retina where rod photoreceptor labeling was less pronounced than that observed for cone photoreceptors. In non-degenerate regions of the RP retina, a marked accumulation of 3H-GABA by the Müller's cells was observed. Few cells exhibited selective uptake of 3H-muscimol, a GABA analog, indicating that few GABAergic neurons remained in the degenerate retina. 3H-dopamine-accumulating cell terminals were observed in the usual positions in the non-degenerate RP retina. In the degenerate region of the RP retina, heavy and diffuse uptake of 3H-GABA and 3H-muscimol, respectively, into broad cellular processes were noted, whereas 3H-dopamine was accumulated by only a few punctate terminals.
mesh_terms: D000368:Aged; D000596:Amino Acids / Q000378:metabolism*; D002829:Choroid / Q000378:metabolism; D046508:Culture Techniques; D005260:Female; D006801:Humans; D007930:Leucine / Q000378:metabolism; D008358:Mannose / Q000378:metabolism; D010786:Photoreceptor Cells / Q000378:metabolism; D012162:Retinal Degeneration / Q000175:diagnosis / Q000378:metabolism*; D012174:Retinitis Pigmentosa / Q000175:diagnosis / Q000378:metabolism*; D014238:Trichloroacetic Acid / Q000378:metabolism; D014529:Uridine / Q000378:metabolism; D014603:Uveal Diseases / Q000175:diagnosis / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D014238:Trichloroacetic Acid; D007930:Leucine; D008358:Mannose; D014529:Uridine