Margret C M Blom-Roosemalen

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The LLC-PK1:MDR1, LLC-PK1 and Caco-2 cell lines were used to investigate whether rhodamine-123 or doxorubicin would be the preferred substrate to study P-glycoprotein (P-gp) functionality in vitro. Both rhodamine-123 and doxorubicin showed highly polarised transport in the Caco-2 cell line and the LLC-PK1:MDR1 cell line, indicating that P-gp is actively(More)
OBJECTIVE To investigate the involvement of P-glycoprotein (Pgp) and the multidrug resistance-associated protein (MRP) on the active transport of the HIV protease inhibitors amprenavir, ritonavir and indinavir. METHODS The transport behaviour of ritonavir, indinavir and amprenavir in the presence and absence of Pgp modulators and probenecid was(More)
Caco-2 monolayers were used to determine whether verapamil enhanced the transport of hydrophilic compounds across epithelial cells. Transepithelial electrical resistance (TEER) measurements, as an indicator of the opening of tight junctions, and transport experiments with fluorescein-Na (Flu) and FITC-dextran Mw 4000 (FD-4) were used to assess the effect.(More)
The effects of sodium salicylate and sodium tauro-24,25-dihydrofusidate (STDHF) on the aqueous permeability of confluent monolayers of Caco-2 cells were studied. Measurements of transepithelial electrical resistance (TEER) showed a concentration-dependent effect of both compounds after apical incubation for 1 hr. Reductions in TEER resulting from EC50(More)
The effect of anisotonic solutions on the enhancement of the transport of hydrophilic model compounds across monolayers of Caco-2 and HT-29.cl19A intestinal epithelial cells was studied. In filter-grown monolayers of the highly differentiated villus-like Caco-2 cell line, a profound and dose-dependent drop in the transepithelial electrical resistance was(More)
The presence and upregulation of adhesion molecules on bovine brain endothelial cells (BBEC) were investigated. Monolayers of BBEC were incubated with lipopolysaccharide (LPS), interleukin-1 beta (rhIL-1 beta), and interleukin-6 (rhIL-6) to simulate in vitro an inflammatory site in the cerebral capillaries. Adhesion of lymphocytes to BBEC increased 4.1-fold(More)
The effects of the cytokines tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 beta and IL-6 on the permeability of monolayers of rat cerebral endothelial cells (RCEC) were investigated to assess potential changes in the integrity of the blood-brain barrier (BBB). RCEC were cultured to tight monolayers with a trans endothelial electrical(More)
A rapid and sensitive assay for quantification of nalbuphine, butorphanol and morphine in blood (50 microL) and brain microdialysate ( approximately 40 microL) samples was developed. Blood samples were extracted with ethyl acetate. Analysis was performed with high-performance liquid chromatography (HPLC) coupled to an electrochemical detector. The mobile(More)
The use of verapamil as an absorption enhancer for the paracellular route in-vivo was studied using FITC-labelled dextran (molecular weight 4000) (FD-4) as a hydrophilic model compound for transport enhancement. The kinetics of FD-4 after intravenous doses of 1 or 10 mg could be described by a two-compartment model with a systemic clearance of approximately(More)