Ornithine aminotransferase in chick embryo tissues.
Ornithine aminotransferase (E. C. 2.6.1.13) deficiency has been found to be associated with congenital atrophy of the choroid and retina of man. A deficiency in this enzyme could be associated in a causal fashion with atrophy, or it could be a coincidental association. To challenge the hypothesis that ornithine aminotransferase activity is required directly or indirectly for maintaining the eye in a functional state, it was of interest to determine the level of activity of this enzyme in normal eye tissue. We report here that the level of ornithine aminotransferase activity in pigment epithelium of chicken is 11 times that found in liver. The level of enzyme activity in retina is 80% of that found in liver. The level of enzyme present in embryonic pigment epithelium is essentially unchanged between the eighth and eighteenth day of incubation. These observations suggest strongly that ornithine aminotransferase activity is involved in maintaining the structure or function of the eye.
D000818:Animals; D001284:Atrophy; D002642:Chick Embryo / Q000201:enzymology*; D002645:Chickens; D002829:Choroid / Q000473:pathology; D006801:Humans; D008099:Liver / Q000201:enzymology; D009953:Ornithine-Oxo-Acid Transaminase / Q000172:deficiency / Q000378:metabolism*; D010857:Pigment Epithelium of Eye / Q000201:enzymology*; D012160:Retina / Q000201:enzymology* / Q000473:pathology; D000637:Transaminases / Q000378:metabolism*
D000637:Transaminases; D009953:Ornithine-Oxo-Acid Transaminase