Cellular pharmacokinetic aspects of reversal effect of itraconazole on P-glycoprotein-mediated resistance of anticancer drugs.

Article Details

Citation

Takara K, Tanigawara Y, Komada F, Nishiguchi K, Sakaeda T, Okumura K

Cellular pharmacokinetic aspects of reversal effect of itraconazole on P-glycoprotein-mediated resistance of anticancer drugs.

Biol Pharm Bull. 1999 Dec;22(12):1355-9.

PubMed ID
10746169 [ View in PubMed
]
Abstract

The reversal effect of itraconazole on P-glycoprotein (P-gp)-mediated resistance of vinblastine, daunorubicin and doxorubicin was analyzed from a cellular pharmacokinetic point of view, namely by [3H]azidopine photoaffinity labeling, intracellular accumulation and transcellular transport experiments. The LLC-GA5-COL150 cells, which expressed human P-gp selectively on the apical membrane due to transfection of MDR1 cDNA into the porcine kidney epithelial cells (LLC-PK1 cells), was used here, since this cell line constructs the monolayer with tight junction, being able to characterize the cellular pharmacokinetics. In LLC-GA5-COL150 cells, itraconazole caused a reversal from resistance as shown by a growth inhibition assay. [3H]Azidopine photoaffinity labeling demonstrated that itraconazole, vinblastine, daunorubicin and doxorubicin showed higher binding ability for P-gp compared with digoxin, suggesting the following results were via P-gp. The intracellular accumulation of [3H]vinblastine, [3H]daunorubicin and [14C]doxorubicin after their application on the basal and apical sides was increased by itraconazole. These changes were similar to the dose modifying factors determined by the growth inhibition assay. However, their basal-to-apical transport was hardly affected by itraconazole, and this was explained by the fact that itraconazole inhibited P-gp, and subsequently increased their intracellular concentration and then the non-P-gp mediated transport from the intracellular space to apical side. The apical-to-basal transport of [3H]vinblastine, [3H]daunorubicin and [14C]doxorubicin was increased by itraconazole, and this was reasonably explained by the inhibition of P-gp, and partly also by the increase of their intracellular concentration via the inhibition of P-gp.

DrugBank Data that Cites this Article

Drug Transporters
DrugTransporterKindOrganismPharmacological ActionActions
DaunorubicinP-glycoprotein 1ProteinHumans
Unknown
Substrate
Inhibitor
Inducer
Details
DigoxinP-glycoprotein 1ProteinHumans
Unknown
Substrate
Inhibitor
Inducer
Details
DoxorubicinP-glycoprotein 1ProteinHumans
Unknown
Substrate
Inhibitor
Inducer
Details
ItraconazoleP-glycoprotein 1ProteinHumans
Unknown
Inhibitor
Details
VinblastineP-glycoprotein 1ProteinHumans
Unknown
Substrate
Inhibitor
Inducer
Details