Linked Life Data

11602674

Source:http://linkedlifedata.com/resource/pubmed/id/11602674

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-10-16
pubmed:abstractText
P-glycoprotein (Pgp) affects the absorption, distribution, and clearance of a variety of compounds. Thus, identification of compounds that are Pgp substrates can aid drug candidate selection and optimization. Our goal was to evaluate three assays used to determine whether compounds are Pgp substrates. Sixty-six compounds were tested in monolayer efflux, ATPase, and calcein-AM assays. Assay results yielded two categories of compounds. Category I (n = 35) exhibited concordance across the assays. Category II (n = 31) revealed differences among the assays that related to the apparent permeability (P(app)) of the compounds. Within category II, two groups were discerned based on the absence (group IIA, n = 10, nontransported substrates) or presence (group IIB, n = 21, transported substrates) of monolayer efflux. Detection of efflux (group IIB) was associated with compounds having low/moderate P(app) values (mean = 16.6 nm/s), whereas inability to detect efflux (group IIA) was associated with compounds having high P(app) values (mean = 535 nm/s). The calcein-AM and ATPase assays revealed Pgp interactions for highly permeable group IIA compounds but were less responsive than monolayer efflux for low/moderate P(app) compounds of group IIB. All assays detected substrates across a broad range of P(app), but the efflux assay was more prone to fail at high P(app), whereas the calcein-AM and ATPase assays were more prone to fail at low P(app). When P(app) is low, efflux is a greater factor in the disposition of Pgp substrates. The efflux assay is more reliable at low/moderate P(app) and is the method of choice for evaluating drug candidates despite low throughput and reliance on liquid chromatography with tandem mass spectrometry.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
299
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
620-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Rational use of in vitro P-glycoprotein assays in drug discovery.
pubmed:affiliation
Preclinical Drug Metabolism and Pharmacokinetics, GlaxoSmithKline, Inc, Research Triangle Park, North Carolina 27709, USA. JP16063@gsk.com
pubmed:publicationType
Journal Article