文章基本信息

标题：Kinetic Characterization of Carrier-Mediated Transport Systems for D-Glucose and Taurocholate in the Everted Sacs of the Rat Colon
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作者：Shigemitsu Tomei ; Mayumi Torimoto ; Yayoi Hayashi 等
期刊名称：Biological and Pharmaceutical Bulletin
印刷版ISSN：0918-6158
电子版ISSN：1347-5215
出版年度：2003
卷号：26
期号：6
页码：899-901
DOI：10.1248/bpb.26.899
出版社：The Pharmaceutical Society of Japan
摘要：The present study was aimed at kinetically characterizing the carrier-mediated transport systems for D -glucose and taurocholate in the rat colon, compared with their respective counterparts in the small intestine. The transport of these compounds was evaluated by measuring the initial uptake into everted intestinal tissue sacs. The uptake of both D -glucose and taurocholate was highly saturable, conforming to Michaelis–Menten kinetics without an appreciable nonsaturable transport component. The Michaelis constant ( K _m) was 0.43 and 0.021 m M , respectively, for D -glucose and taurocholate and the maximum transport rate ( J _max) was 0.82 and 0.056 nmol/min/100 mg wet tissue weight (wtw), respectively. For both compounds, these values of K _m and J _max in the colon were one to three orders of magnitude smaller than those in the small intestine, suggesting that the transport systems in the colon have by far a higher affinity and a lower transport capacity than their counterparts in the small intestine. However, it is now evident from kinetic studies that carrier-mediated transport systems for D -glucose and taurocholate are also present in the colon. It will be interesting to explore the possibility that they could be used for oral drug delivery via the colon. Their physiological roles would also be of interest.
关键词：D -glucose;taurocholate;carrier-mediated transport;colon;rat