Retinal is the essential form of retinoid for storage and transport in the adult of the ascidian Halocynthia roretzi
Retinal is the essential form of retinoid for storage and transport in the adult of the ascidian Halocynthia roretzi
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DOI：
10.1016/j.cbpc.2004.07.014
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发表时间：
2004-12-01
影响因子：
2.2
通讯作者：
Seki, T
中科院分区：
文献类型：
--
作者：
Irie, T;Kajiwara, S;Seki, T
采用高效液相色谱法分析了罗氏盐萼海鞘（Halocynthia roretzi）成虫各器官（性腺、体壁肌、肝胰腺、鳃、血淋巴细胞和血淋巴血浆）中的维甲酸含量。视网膜（RAL）见于所有检查器官，PAL（≥ 99%）多位于GND和BWM。所有器官均不含显著量的视黄醇（ROL）或视黄酯（RE）。脂滴是星状细胞（脊椎动物的再生储存细胞）的特征，通过显微镜观察在GND、BWM和HP中不能发现。这些结果表明，这种海鞘缺乏RE储存机制，这是普遍存在于成年脊椎动物。RAL的数量和分布与生殖周期有关，呈现出年变化。在夏季，生长季节，RAL存在于GND和BWM中，比例约为3：2。从夏季到冬季，GND的RAL逐渐增加，伴随着BWM的RAL减少。在冬季，产卵季节，大部分RAL存在于GND（约。98%）。RAL似乎首先在BWM中积累，并随卵黄积累转运至卵母细胞。ROL和RE不参与类维生素A的储存和运输。本研究的结果强烈表明，视黄酸（RA）是由两步酶促反应产生的：类胡萝卜素裂解为RAL，然后RAL氧化为RA，并且前脊椎动物脊索动物缺乏ROL代谢系统。(C)2004年爱思唯尔公司All rights reserved.
Retinoids in the organs (gonad [GND], body wall muscle [BWM], hepatopancreas [HP], gill, hemolymph cells and hemolymph plasma) of the adult ascidian Halocynthia roretzi were analyzed by high performance liquid chromatography. Retinal (RAL) occurred in every organ examined, and most of PAL (greater than or equal to99%) was localized in the GND and BWM. None of the organs contained significant amounts of retinol (ROL) or retinyl ester (RE). Lipid droplets, which are characteristic of stellate cells (RE-storing cells of vertebrates), could not be found in the GND, BWM and HP by microscopic observations. These results indicate that this ascidian lacks the RE-storing mechanism, which is ubiquitous in adult vertebrates. The amount and localization of RAL showed the annual change in relation to the reproductive cycle. During summer, the growing season, RAL was present in both GND and BWM at a ratio of about 3:2. From summer to winter, RAL in the GND gradually increased, concomitant with the decrease of RAL in the BWM. In winter, the spawning season, most of RAL was present in the GND (ca. 98%). RAL appears to be accumulated first in the BWM and transported to oocytes accompanying yolk accumulation. ROL and RE were not implicated in the storage and transport of retinoids. The results in the present research strongly suggest that retinoic acid (RA) is produced by the two-step enzymatic reaction: carotenoid cleavage to RAL followed by RAL oxidation to RA and that the prevertebrate chordate lacks ROL-metabolizing systems. (C) 2004 Elsevier Inc. All rights reserved.