Synthetic activities of cultured retinal pigment epithelial cells from a patient with retinitis pigmentosa.

We established cultures of retinal pigment epithelial (RPE) cells from four normal individuals and a 56-year-old male patient with autosomal-dominant retinitis pigmentosa (RP) and examined the synthetic activities of these cells via radiolabeling experiments. The uptake of radioactive precursors per milligram of cell protein by RPE cells from the patient with RP was significantly higher than that found in the normal control cells. It appears that the net synthetic activities of glycosaminoglycans and proteins in our patient's cells were enhanced and that the cell metabolism was altered. This finding suggests that malfunctioning of the RPE cells may play a role in the deterioration of photoreceptor functions seen in at least some patients with autosomal-dominant RP.