Fig. 1. Accumulation of retinyl esters in the retina and retinal pigment epithelium (RPE) of adult chicken eye. Chicken were decapitated and the heads were transported in the dark (2 h) to the laboratory. Eye lids were removed and eyes were light adapted (2000 lux) for two hours prior to dissection. Retina was dissected free from RPE, and eye tissues were homogenized in Tris-HCl (pH 7.5) and extracted for retinoids by ethanol and hexane. (A) HPLC analysis of retinoids extracted from one retina of 2 h dark-adapted (top) or one retina of 2 h light-adapted (bottom) chicken eyes. Absorbance was monitored at 318 nm in optical density units. Peak I is 11-cis retinyl ester, with a retention time of 5.8 min and a UV spectrum with an absorption maximum at 318 nm (inset). (B) HPLC analysis of retinoids extracted from two RPE of 2 h dark-adapted (top) or two RPE of 2 h light-adapted (bottom) chicken eyes. Absorbance was monitored at 325 nm in optical density units. Peak II is all-trans retinyl ester, with a retention time of 6.5 min and a UV spectrum with an absorption maximum at 325 nm (inset). Accumulation of 11-cis (open circles) and all-trans (filled circles) retinyl ester in the (C) retina or (D) RPE as a function of time in response to light (open bar) and dark (shaded bar) adaptation. Means ± S.E.M. were calculated from results of four experiments. For each of the four experiments, retinoid extracts from individual retina or RPE were analyzed by HPLC and results from two retinae or two RPE (per time point) were averaged (N=2).