Reference

Inhibitory effect of zinc on PEPT1-mediated transport of glycylsarcosine and b-lactam antibiotics in human intestinal cell line Caco-2

Inhibitory effect of zinc on PEPT1-mediated transport of glycylsarcosine and b-lactam antibiotics in human intestinal cell line Caco-2. Okamura, Miyako; Terada, Tomohiro; Katsura, Toshiya; Saito, Hideyuki; Inui, Ken-ichi (Faculty of Medicine, Kyoto University Hospital, Department of Pharmacy, Kyoto University, Kyoto 606-8507, Japan). Pharmaceutical Research, 20(9), 1389-1393 (English) 2003 Kluwer Academic/Plenum Publishers. CODEN: PHREEB. ISSN: 0724-8741. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Section cross-reference(s): 18 The aim of this study was to examine the effects of zn on the intestinal peptide transporters (PEPT1 and basolateral peptide transporter) and to elucidate the mechanism of the interactions. Caco-2 cells were pretreated with Zn, and the uptake studies were carried out.There are some reagents with their cas registry numbers 7440-66-6 and 97519-39-6 are used in this study. Zinc treatment resulted in the inhibition of [14C]glycylsarcosine (Gly-Sar) uptake via PEPT1 in a concn.-dependent manner, whereas it showed moderate inhibitory effect on the basolateral peptide transporter. Zinc also inhibited the uptake of oral b-lactam antibiotics such as ceftibuten and cephradine by PEPT1. Kinetic anal. showed that Zn treatment increased Km values without affecting Vmax values of the [14C]Gly-Sar uptake. The inhibition of [14C]Gly-Sar uptake induced by Zn was obsd. in the presence of an H+ gradient but not in the absence of an H+ gradient. These results indicate that Zn is a competitive inhibitor of PEPT1. Zinc inhibited the PEPT1 function, possibly by interacting with His residues of PEPT1 that are part of an H+-binding site. These findings would provide important information for clin., physiol., and biochem. aspects of peptide transporters. .

Antibacterial activity of cefpodoxime in comparison with cefixime, cefdinir, cefetamet, ceftibuten, loracarbef, cefprozil, BAY 3522, cefuroxime, cefaclor and cefadroxil

Antibacterial activity of cefpodoxime in comparison with cefixime, cefdinir, cefetamet, ceftibuten, loracarbef, cefprozil, BAY 3522, cefuroxime, cefaclor and cefadroxil. Bauernfeind, A.; Jungwirth, R. (Max-von-Pettenkofer-Inst., Munich W-8000/2, Germany). Infection (Munich), 19(5), 353-62 (English) 1991. CODEN: IFTNAL. ISSN: 0300-8126. DOCUMENT TYPE: Journal CA Section: 10 (Microbial, Algal, and Fungal Biochemistry) The new oral cephalosporins cefpodoxime, cefixime, cefdinir, cefetamet, and ceftibuten demonstrate enhanced activity against Enterobacteriaceae susceptible to the established compds. as well (e.g. cefuroxime, cefaclor, cefadroxil). In addn., cefpodoxime, cefixime, cefdinir, cefetamet, and ceftibuten include in their spectrum spp. hitherto resistant to oral cephalosporins (Proteus vulgaris, Providencia spp., Yersinia enterocolitica). The majority of these compds. demonstrate relevant activity (MIC50 ￡2 mg/L) against Enterobacter spp., Citrobacter freundii, Serratia spp., and Morganella morganii. Ceftibuten is the most potent oral cephalosporin against most of the Enterobacteriaceae. Nonfermentative bacilli (Acinetobacter spp., Pseudomonas spp.) remain completely resistant to oral cephalosporins (except some Acinetobacter spp. against cefdinir and Pseudomonas cepacia against ceftibuten).In this experiment, several chemicals are used like 97519-39-6 and 76470-66-1 Antistaphylococcal activity for oral cephalosporins is highest for cefdinir, followed by BAY 3522, cefprozil, cefuroxime, and cefpodoxime. Loracarbef, cefaclor,and cefadroxil are about equally active, while the other compds. are only weakly active (cefixime) or inactive (cefetamet, ceftibuten). .