An Electrically Tight In Vitro Blood–Brain Barrier Model Displays Net Brain-to-Blood Efflux of Substrates for the ABC Transporters, P-gp, Bcrp and Mrp-1
Journal Title: The AAPS Journal - Year 2014, Vol 16, Issue 5
Abstract
Efflux transporters of the ATP-binding cassette superfamily including breast cancer resistance protein (Bcrp/Abcg2), P-glycoprotein (P-gp/Abcb1) and multidrug resistance-associated proteins (Mrp’s/Abcc’s) are expressed in the blood–brain barrier (BBB). The aim of this study was to investigate if a bovine endothelial/rat astrocyte in vitro BBB co-culture model displayed polarized transport of known efflux transporter substrates. The co-culture model displayed low mannitol permeabilities of 0.95 ± 0.1 · 10−6 cm·s−1 and high transendothelial electrical resistances of 1,177 ± 101 Ω·cm2. Bidirectional transport studies with 3H-digoxin, 3H-estrone-3-sulphate and 3H-etoposide revealed polarized transport favouring the brain-to-blood direction for all substrates. Steady state efflux ratios of 2.5 ± 0.2 for digoxin, 4.4 ± 0.5 for estrone-3-sulphate and 2.4 ± 0.1 for etoposide were observed. These were reduced to 1.1 ± 0.08, 1.4 ± 0.2 and 1.5 ± 0.1, by addition of verapamil (digoxin), Ko143 (estrone-3-sulphate) or zosuquidar + reversan (etoposide), respectively. Brain-to-blood permeability of all substrates was investigated in the presence of the efflux transporter inhibitors verapamil, Ko143, zosuquidar, reversan and MK 571 alone or in combinations. Digoxin was mainly transported via P-gp, estrone-3-sulphate via Bcrp and Mrp’s and etoposide via P-gp and Mrp’s. The expression of P-gp, Bcrp and Mrp-1 was confirmed using immunocytochemistry. The findings indicate that P-gp, Bcrp and at least one isoform of Mrp are functionally expressed in our bovine/rat co-culture model and that the model is suitable for investigations of small molecule transport.
Authors and Affiliations
Hans Christian Helms, Maria Hersom, Louise Borella Kuhlmann, Lasina Badolo, Carsten Uhd Nielsen, Birger Brodin
Keywords
Related Articles
- EP ID EP681671
- DOI 10.1208/s12248-014-9628-1
- Views 60
- Downloads 0
Does the Recent Growth of Aquaculture Create Antibiotic Resistance Threats Different from those Associated with Land Animal Production in Agriculture?
The online version of this article (doi:10.1208/s12248-015-9722-z) contains supplementary material, which is available to authorized users.
Reduction of a Whole-Body Physiologically Based Pharmacokinetic Model to Stabilise the Bayesian Analysis of Clinical Data
The online version of this article (doi:10.1208/s12248-015-9840-7) contains supplementary material, which is available to authorized users.
Polymeric Nanocarriers for Transport Modulation across the Pulmonary Epithelium: Dendrimers, Polymeric Nanoparticles, and their Nanoblends
The online version of this article (doi:10.1208/s12248-014-9588-5) contains supplementary material, which is available to authorized users.
Assessment of fertility in male rats after extended chemical castration with a GnRH antagonist
The purpose of this study was to assess whether male rats whose testosterone levels were suppressed to castration levels (<0.5 ng/mL) for a 1-year period by the sustained delivery of orntide acetate, a GnRH antag...
Role of the breast cancer resistance protein (ABCG2) in drug transport
The 72-kDa breast cancer resistance protein (BCRP) is the second member of the subfamily G of the human ATP binding cassette (ABC) transporter superfamily and thus also designated as ABCG2. Unlike P-glycoprotein and MRP1...