Absorption properties and P-glycoprotein activity of modified Caco-2 cell lines

Korjamo, Timo; Honkakoski, Paavo; Toppinen, Marjo-Riitta; Niva, Sanna; Reinisalo, Mika; Palmgrén, Joni; Mönkkönen, Jukka

doi:10.1016/j.ejps.2005.06.004

Cited by 35 publications

(28 citation statements)

References 61 publications

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“…MDR1, MRP2 and BCRP mRNA levels were measured by quantitative RT-PCR (qRT-PCR) using custom made primers and probes (25). FAM-labeled Assay on Demand TaqMan® Gene Expression Assays (Applied Biosystems, Foster City, CA, USA) were used to measure mRNA levels of MRP1 (Hs00219905_m1), MRP3 (Hs00358656_m1), MRP4 (Hs00195260_m1), MRP5 (Hs00981071_m1) and MRP6 (Hs00184566_m1).…”

Section: Extraction Of Rna and Quantitative Rt-pcrmentioning

confidence: 99%

Efflux Protein Expression in Human Retinal Pigment Epithelium Cell Lines

Mannermaa

Vellonen

Ryhänen³

et al. 2009

Pharm Res

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Section: Extraction Of Rna and Quantitative Rt-pcrmentioning

confidence: 99%

Efflux Protein Expression in Human Retinal Pigment Epithelium Cell Lines

Mannermaa

Vellonen

Ryhänen³

et al. 2009

Pharm Res

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“…Caco-2 cells (ATCC HTB-37, Manassas, VA, USA) were cultured as previously described (11). Briefly, Caco-2 cells (passages 35-50) were maintained subconfluent in cell culture flasks and subcultured twice a week.…”

Section: Cell Culturementioning

confidence: 99%

The Asymmetry of the Unstirred Water Layer in Permeability Experiments

et al. 2008

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“…Apparent absorptive and secretory permeability coefficients (P app ) were determined for P-glycoprotein substrates digoxin and quinidine at various donor concentrations using radiolabeled compound (1 l/ml) in the donor chamber as a marker. The permeability experiments were performed in both apical-to-basolateral (AB) and basolateral-to-apical (BA) directions as described previously (Korjamo et al, 2005). Passive permeability (P pass ) was studied at each drug concentration with assay buffer containing the P-glycoprotein inhibitor, GF120918 (2 M).…”

Section: Methodsmentioning

confidence: 99%

“…Caco-2/WT (HTB-37; American Type Culture Collection, Manassas, VA) and Caco-2/hPXR (Korjamo et al, 2005) cell lines were cultured as described previously (Korjamo et al, 2005).…”

Section: Methodsmentioning

confidence: 99%

Decrease in Intracellular Concentration Causes the Shift in K_m Value of Efflux Pump Substrates

Korjamo

Kemiläinen²,

Heikkinen³

et al. 2007

Drug Metab Dispos

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ABSTRACT:Passive permeability and active efflux are parallel processes in transcellular flux. Therefore, the observed kinetics of a transporter substrate depends on both of these factors. The transporter expression has been shown to affect both the apparent K m and V max values. Kinetic parameters can be obtained from various experimental settings, but these do not necessarily reflect the situation in transcellular flux. Kinetic absorption models need reliable estimates of saturable kinetics when accurate in silico predictions are to be made. The effect of increasing P-glycoprotein expression on apparent transport kinetics was studied using quinidine and digoxin as model compounds. The intracellular concentrations of drugs during the transport process were also measured. A dynamic simulation model was constructed to study the observed data. The apparent K m and V max values increased as the P-glycoprotein expression increased. Simulations reproduced the shift in both kinetic parameters as a function of efflux pump expression. In addition, the apparent K m value showed a strong inverse relationship to the passive permeability. In contrast, the apparent V max value reached a maximum at intermediate passive permeability and declined above and below this passive permeability. The true V max and K m values were never reached. The shift in K m was assigned to a decrease in intracellular concentration at the Pglycoprotein interaction site with both experimental and simulation data. In conclusion, the apparent kinetic parameters in transcellular permeability assays depend on passive permeability and efflux pump activity. Therefore, parameters that are obtained from in vitro assays should be cautiously applied to in vivo predictions.

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Absorption properties and P-glycoprotein activity of modified Caco-2 cell lines

Cited by 35 publications

References 61 publications

Efflux Protein Expression in Human Retinal Pigment Epithelium Cell Lines

Efflux Protein Expression in Human Retinal Pigment Epithelium Cell Lines

The Asymmetry of the Unstirred Water Layer in Permeability Experiments

Decrease in Intracellular Concentration Causes the Shift in K_m Value of Efflux Pump Substrates

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Absorption properties and P-glycoprotein activity of modified Caco-2 cell lines

Cited by 35 publications

References 61 publications

Efflux Protein Expression in Human Retinal Pigment Epithelium Cell Lines

Efflux Protein Expression in Human Retinal Pigment Epithelium Cell Lines

The Asymmetry of the Unstirred Water Layer in Permeability Experiments

Decrease in Intracellular Concentration Causes the Shift in Km Value of Efflux Pump Substrates

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Decrease in Intracellular Concentration Causes the Shift in K_m Value of Efflux Pump Substrates