抄録
Human gyrate atrophy of the choroid and retina was found to accompany hereditary deficiency of ornithine oxoacid aminotransferase (EC 2.6.1.13) and hyperornithinemia. I have maintained to study ornithine metabolism of rat liver for long time, but recently have turned to study ocular ornithine metabolism using special experience in this field and reached some etiological aspects. Contents : I. Ocular ornithine metabolism II. Nature of ocular ornithine oxoacid aminotransferase III. Properties of purified ∇^1_pyrroline-5-carboxylate reductase from bovine retina IV. Biochemical studies on retinal degeneration using retinal degeneration mouse as a model of the gyrate atrophy of the choroid and retina We have found the occurrence of active ornithineproline pathway, which is first catalized by ornithine oxoacid aminotransferase and secondary by pyrroline-5-carboxylate reductase, in the retinas of mouse and cow and probably it also exists in human retina. In C3H retinal degeneration mouse, we found a marked decrease of pyrroline-5-carboxylate reductase activity and ornithineproline converting activity in the retina after 10th postnatal day. Since this pathway seems to be a sole endogenous proline suppliant in the retina, the deficiency of ornithine oxoacid aminotransferasc in the gyrate atrophy should bring a deficiency of proline supplement to the some critical locus in the retina.
