Linked Life Data

3446770

Source:http://linkedlifedata.com/resource/pubmed/id/3446770

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1988-5-24
pubmed:abstractText
By using isolated rat hepatocytes, the mechanism of uptake of a zwitterionic beta-lactam antibiotic, cephalexin, was clarified. The uptake followed the combination of saturable carrier-mediated and nonsaturable first-order rate processes. The kinetic parameters were estimated as follows (mean +/- SD): maximum uptake rate (Vmax), 2.28 +/- 0.24 nmol/min/mg of protein; Michaelis constant (Kt), 6.28 +/- 0.31 mM and first-order rate constant (kd), 0.11 +/- 0.012 nmol/min/mg of protein/mM. There was no inhibitory effect by amino acids, dipeptides or organic cations, whereas an organic anion, probenecid, markedly inhibited the hepatic uptake of cephalexin. Several beta-lactam antibiotics including zwitterionic and anionic derivatives inhibited cephalexin uptake significantly. The inhibition kinetics revealed that benzylpenicillin and the stereo-isomer l-cephalexin competitively inhibited cephalexin uptake. Furthermore, the efflux of cephalexin from the cells was stimulated by adding benzylpenicillin in the extracellular medium. These results demonstrated that all beta-lactam antibiotics have a common transport system with an organic anion such as probenecid, irrespective of their ionic charges, though a cationic charge on the molecule is less advantageous for being recognized by the carrier system.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0386-846X
pubmed:author
pubmed:issnType
Print
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
632-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Transport mechanism of cephalexin in isolated hepatocytes.
pubmed:affiliation
Faculty of Pharmaceutical Sciences, Kanazawa University Takara-machi, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't