P-Glycoprotein in cell cultures: a combined approach to study expression, localisation, and functionality in the confocal microscope.
Eur J Pharm Sci
; 12(1): 69-77, 2000 Nov.
Article
in En
| MEDLINE
| ID: mdl-11121735
ABSTRACT
Madin Darby canine kidney (MDCK) cells transfected with the multidrug resistance mdr1 gene, MDR1-MDCK (Pastan et al., 1988, Proc. Natl. Acad. Sci. USA 85 4486-4470), were used in a combined approach to study expression, localisation and functionality of the P-glycoprotein (P-gp) membrane transporter in the same cell culture preparations. Cells were characterised with regard to their growth curve, transepithelial electrical resistance (TEER), and cytoarchitecture. Efflux of the P-gp substrate rhodamine123 (rho123) was monitored with confocal laser scanning microscopy (CLSM). The transfected cells grew in multilayers. After reaching confluence they exhibited a complete tight junction (TJ) network. P-gp was strongly expressed at the uppermost apical surface of the multilayer already after 4 days in culture. The lower cell layers were not clearly polarised. P-gp-mediated transport could be followed by efflux of the fluorescent rho123 from the cells into the apical extracellular space. Verapamil, a P-gp inhibitor, significantly decreased efflux. For MDCK parent cells the rho123 assay was negative up to about day 20, and only at later times (day 25) low P-gp activity was detected. These results clearly show that despite the fact that the transfected cells form irregular layers, they provide a good model for screening of P-gp substrates and inhibitors.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
ATP Binding Cassette Transporter, Subfamily B, Member 1
Limits:
Animals
Language:
En
Journal:
Eur J Pharm Sci
Journal subject:
FARMACIA
/
FARMACOLOGIA
/
QUIMICA
Year:
2000
Document type:
Article
Affiliation country:
Suiza