title: alpha-Tocopherol in the developing rat retina: a high pressure liquid chromatographic analysis.
abstract: High pressure liquid chromatography was used to measure alpha-tocopherol in the retinas of rats reared in a cyclic light or dark environment. These measurements were performed on extracts of whole retinas during the developmental period, 18-60 days, and on isolated ROS from adult animals. Similar alpha-tocopherol determinations were performed on retinas and isolated ROS following exposure of rats to intense visible light for 24 hr periods. The results show that alpha-tocopherol is chromatographically separated from the vitamin A derivatives found in the retina and is pure, as judged by mass spectrometry. In the retinas of cyclic light and dark reared rats, alpha-tocopherol accumulates in an age dependent fashion, so that at 60 days the level is nearly double that of animals at 18-20 days of age (P less than 0.001). Because the age dependent accumulation of rhodopsin is greater in dark reared rats, the average molar ratio of rhodopsin to alpha- tocopherol in the retina of dark reared animals is 25% higher than in cyclic light rats. Following exposure of rats to intense visible light for 24 hr periods, alpha-tocopherol concentrations in the retina were unchanged from the levels in control animals. In adult animals the concentration of alpha-tocopherol in ROS is 2.5-3.5 times higher than in whole retina. ROS from adult cyclic light reared rats also contain an average of 43% more alpha-tocopherol per mg protein than ROS from dark maintained animals (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000367:Age Factors; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003624:Darkness; D004780:Environment, Controlled; D008027:Light; D051381:Rats; D011919:Rats, Inbred Strains; D012160:Retina / Q000254:growth & development / Q000378:metabolism*; D012374:Rod Cell Outer Segment / Q000378:metabolism; D014810:Vitamin E / Q000378:metabolism*
chemical_list: D014810:Vitamin E