Rahman Mohammad Lutfur, Yoshida Kazuyuki, Maeda Isamu, Tanaka Hideuki, Sugita Shoei
Department of Animal Science, Faculty of Agriculture, Utsunomiya University, 350 Minemachi, Utsunomiya, Tochigi 321-8505, Japan.
Zoolog Sci. 2010 Jun;27(6):514-21. doi: 10.2108/zsj.27.514.
The topography of cone oil droplets and their carotenoids were investigated in the retina of jungle crow (Corvus macrorhynchos). Fresh retina was sampled for the study of retinal cone oil droplets, and extracted retinal carotenoids were saponified using methods adapted from a recent study, then identified with reverse-phase high-performance liquid chromatography (HPLC). To assess the effects of saponification conditions on carotenoid recovery from crow retina, we varied base concentration and total time of saponification across a wide range of conditions, and again used HPLC to compare carotenoid concentrations. Based on colors, at least four types of oil droplets were recognized, i.e., red, orange, green, and translucent, across the retina. With an average of 91,202 /mm(2), density gradually declines in an eccentric manner from optic disc. In retina, the density and size of droplets are inversely related. In the peripheral zone, oil droplets were significantly larger than those of the central area. The proportion of orange oil droplets (33%) was higher in the central area, whereas green was predominant in other areas. Three types of carotenoid (astaxanthin, galloxanthin and lutein), together with one unknown carotenoid, were recovered from the crow retina; astaxanthin was the dominant carotenoid among them. The recovery of carotenoids was affected by saponification conditions. Astaxanthin was well recovered in weak alkali (0.06 M KOH), in contrast, xanthophyllic carotenoids were best recovered in strong alkali (0.6 M KOH) after 12 h of saponification at freeze temperature.
在丛林鸦（Corvus macrorhynchos）的视网膜中研究了视锥细胞油滴及其类胡萝卜素的分布情况。采集新鲜视网膜用于视锥细胞油滴的研究，提取的视网膜类胡萝卜素采用近期一项研究中的方法进行皂化处理，然后用反相高效液相色谱法（HPLC）进行鉴定。为了评估皂化条件对从乌鸦视网膜中回收类胡萝卜素的影响，我们在广泛的条件范围内改变碱浓度和皂化总时间，并再次使用HPLC比较类胡萝卜素浓度。基于颜色，在整个视网膜中至少识别出四种类型的油滴，即红色、橙色、绿色和半透明油滴。平均密度为91,202个/mm²，从视盘开始以离心方式逐渐下降。在视网膜中，油滴的密度和大小呈负相关。在外周区域，油滴明显大于中央区域的油滴。橙色油滴在中央区域的比例较高（33%），而在其他区域绿色油滴占主导。从乌鸦视网膜中回收了三种类胡萝卜素（虾青素、鸡油菌黄质和叶黄素）以及一种未知类胡萝卜素；其中虾青素是主要的类胡萝卜素。类胡萝卜素的回收率受皂化条件影响。在弱碱（0.06 M KOH）中虾青素回收率良好，相比之下，在冷冻温度下皂化12小时后，在强碱（0.6 M KOH）中亲水性类胡萝卜素回收率最佳。
