Absorption, distribution, and secretion of epicatechin and quercetin in the rat
Absorption, distribution, and secretion of epicatechin and quercetin in the rat
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DOI：
10.1016/j.nutres.2004.10.013
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发表时间：
2005-03-01
影响因子：
4.5
通讯作者：
van Amelsvoort, JMM
中科院分区：
文献类型：
--
作者：
Abrahamse, SL;Kloots, WJ;van Amelsvoort, JMM
黄烷醇和黄酮醇被认为是人类饮食中最重要的单体类黄酮。在这项研究中，我们比较了黄烷醇表儿茶素和黄酮醇栎素及其所有代谢物在大鼠体内的表观吸收、血药浓度、组织分布和排泄。为此，回肠吻合的大鼠和门静脉内装有永久性插管的大鼠通过食道内的管子给药~H标记的表儿茶素或C-14标记的槲皮素。分别从回肠造口和插管的不同时间点采集消化液和血浆样本，并进行放射性分析。此外，还收集了24小时的粪便和尿样，并对其进行了放射性含量分析。最后，在研究结束时，从身体不同部位采集组织样本，以确定累积的放射性标记量。表儿茶素和槲皮素的最大血药浓度和达峰时间相似。表儿茶素的放射性迅速从循环中清除，但从给药后6小时起再次增加。在摄入后3~7小时内到达回肠末端的放射性，在摄入后24小时出现在不同胃肠段的放射性，以及在摄入后24小时内从粪便中排出的放射性的量，表儿茶素和槲皮素相似。24小时的尿液排泄量表明，在摄入后的前12小时内，表儿茶素的放射性排泄量比槲皮素更多。表儿茶素和槲皮素在摄食后24小时内未在受试器官和组织中积聚，但胃肠道节段除外。总而言之，表儿茶素和槲皮素在24小时内的组织积累量和排泄率似乎相似，但在这些类黄酮类及其代谢物的尿排泄方面观察到了差异。(C)2005 Elsevier Inc.保留所有权利。
Flavanols and flavonols are thought to be the most important monomeric flavonoids in the human diet. In this study, we compared the apparent absotption, blood concentrations, tissue distribution, and excretion of the flavanol epicatechin and flavonol quercetin, including all metabolites thereof, in the rat. For this, ileostomized rats and rats equipped with a permanent cannula in the portal vein were administered either 3 H-labeled epicatechin or C-14-labeled quercetin through a tube in the esophagus. Digesta and blood plasma samples were collected at various time points from the ileostomy and cannula, respectively, and analyzed for radioactivity. In addition, 24-hour feces and urine samples were collected and analyzed for radioactive content. Finally, at the termination of the study, tissue samples from various parts of the body were taken to determine the amount of accumulated radioactive label. Maximum plasma concentrations and time to maximum were similar for epicatechin and quercetin equivalents. Radioactivity from epicatechin was rapidly cleared from the circulation, but increased again from 6 hours after administration onward. The amount of radioactivity reaching the end of the ileum during 3 to 7 hours after ingestion, which presents in the different gastrointestinal segments at 24 hours after ingestion, as well as the amount of radioactivity excreted in feces during 24 hours after ingestion, was similar for epicatechin and quercetin. The 24-hour urinary excretion showed that more radioactivity from epicatechin is excreted during the first 12 hours after ingestion than from quercetin. Epicatechin and quercetin had not accumulated in tested organs and tissues at 24 hours after ingestion, except for the gastrointestinal segments. In conclusion, tissue accumulation in 24 hours and fecal secretion rates of epicatechin and quercetin appeared to be similar, but differences were observed with respect to the urinary excretion of these flavonoids and their metabolites. (c) 2005 Elsevier Inc. All rights reserved.