Abstract
There is substantial evidence that the primary structure involved in chloroquine retinopathy is the retinal pigment epithelium (RPE) and that this drug, like the phenothiazines, stores in RPE in high concentration. Experiments reported here show that in concentrations of approximately 5 x 10-4M chloroquine inhibits protein synthesis in RPE without inhibiting amino acid uptake as measured with 14C-labeled phenylalanine, lysine, and leucine. Similar effects are observed with hydroxychloroquine, desethylchloroquine, and quinine. These findings strongly suggest that after storage in RPE the direct toxic effect of the drug is inhibition of protein synthesis.