著者
AKIRA TSUJI HIDEKI HIROOKA IKUMI TAMAI TETSUYA TERASAKI
出版者
JAPAN ANTIBIOTICS RESEARCH ASSOCIATION
雑誌
The Journal of Antibiotics (ISSN:00218820)
巻号頁・発行日
vol.39, no.11, pp.1592-1597, 1986 (Released:2006-04-19)
参考文献数
18
被引用文献数
12 16

Transport of a new cephalosporin developed for oral use, FK089, has been studied with the rat everted small intestine in vitro. Uptake was found to be pH-dependent with the maximum rate at an acidic pH below 5 and with a 5-fold lower rate at pH 7.0. The shape of the pH-rate profile was very similar to that of cefixime and different from that of pH-lipophilicity profile of FK089. The saturation kinetics of the uptake of FK089 were demonstrated at pH 5.0. By correcting the nonsaturable rate process, the kinetics of the mutual inhibition of FK089 uptake by cefixime and cefixime uptake by FK089 were all consistent with competitive type inhibition. The results indicate that carrier-mediated transport is responsible for transport of cephem antibiotics without an α-amino group in the side chain at the 7-position of the cephem nucleus in the intestinal brush-border membrane.