Journal article
If the K-I Is Defined by the Free Energy of Binding to P-Glycoprotein, Which Kinetic Parameters Define the IC50 for the Madin-Darby Canine Kidney II Cell Line Overexpressing Human Multidrug Resistance 1 Confluent Cell Monolayer?
Drug metabolism and disposition, v 38(2), pp 260-269
01 Feb 2010
PMID: 19889884
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
From previous fits of drug transport kinetics across confluent Madin-Darby canine kidney II cell line overexpressing human multidrug resistance 1 cell monolayers, we found that a drug's binding constant to P-glycoprotein (P-gp) was significantly smaller than its IC50 when that drug was used as an inhibitor against another P-gp substrate. We tested several IC50 candidate functions, including the standard function, the Kalvass-Pollack function, and the efflux ratio, to determine whether any of them yielded an IC50 = K-I, as would be expected for water-soluble enzymes. For the confluent cell monolayer, the IC50/K-I ratio is greater than 1 for all candidate functions tested. From the mass action kinetic model, we have derived a simple approximate equation that shows how the IC50/K-I ratio depends on the elementary rate constants from our mass action model. Thus, the IC50 will differ between cell lines and tissues, for the same probe substrate and inhibitor, if there are different membrane concentrations of P-gp, or the probe substrate's elementary rate constants, partition coefficient, binding constant to P-gp, passive permeability, and ability to access the other transporters ( if any) in the two cell lines. The mass action model and the approximate equation for the IC50/K-I ratio derived here can be used to estimate the elementary rate constants needed to extrapolate in vitro drug-drug interactions for compounds to the in vivo environment.
Metrics
Details
- Title
- If the K-I Is Defined by the Free Energy of Binding to P-Glycoprotein, Which Kinetic Parameters Define the IC50 for the Madin-Darby Canine Kidney II Cell Line Overexpressing Human Multidrug Resistance 1 Confluent Cell Monolayer?
- Creators
- Annie Albin Lumen - Drexel UniversityPoulomi Acharya - Drexel Univ, Dept Biol, Philadelphia, PA 19104 USAJoseph W. Polli - GlaxoSmithKline, Preclin Drug Metab & Pharmacokinet, Res Triangle Pk, NC USAAndrew Ayrton - GlaxoSmithKline, Preclin Drug Metab & Pharmacokinet, Welwyn Garden City, Herts, EnglandHarma Ellens - GlaxoSmithKline, Preclin Drug Metab & Pharmacokinet, King Of Prussia, PA USAJoe Bentz - Drexel Univ, Dept Biol, Philadelphia, PA 19104 USA
- Publication Details
- Drug metabolism and disposition, v 38(2), pp 260-269
- Publisher
- Amer Soc Pharmacology Experimental Therapeutics
- Number of pages
- 10
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Biology
- Web of Science ID
- WOS:000273726900007
- Scopus ID
- 2-s2.0-76149115533
- Other Identifier
- 991019168725504721
UN Sustainable Development Goals (SDGs)
This publication has contributed to the advancement of the following goals:
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Industry collaboration
- Domestic collaboration
- International collaboration
- Web of Science research areas
- Pharmacology & Pharmacy