Evidence for a Carrier-Mediated Transport System in the Small Intestine Available for FK089, a New Cephalosporin Antibiotic Without an Amino Group

Akira Tsuji, Hideki Hirooka, Ikumi Tamai, Tetsuya Terasaki

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

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-lipophi-licity 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 a-amino group in the side chain at the 7-position of the cephem nucleus in the intestinal brush-border membrane.

Original languageEnglish
Pages (from-to)1592-1597
Number of pages6
Journalthe journal of antibiotics
Volume39
Issue number11
DOIs
Publication statusPublished - 1986

ASJC Scopus subject areas

  • Pharmacology
  • Drug Discovery

Fingerprint

Dive into the research topics of 'Evidence for a Carrier-Mediated Transport System in the Small Intestine Available for FK089, a New Cephalosporin Antibiotic Without an Amino Group'. Together they form a unique fingerprint.

Cite this