Bcrp does not influence transport of nitrofurantoin across the blood-brain barrier at different ages
(English)Manuscript (preprint) (Other academic)
In the blood-brain barrier (BBB), tight junction proteins together with active efflux transporters efficiently restrict access of many compounds to the brain. The contribution of breast cancer resistance protein (Bcrp, coded by Abcg2) for drug efflux in the BBB is not clear. The aim of this study was to investigate the contribution of Bcrp in the rat BBB and how development affects distribution of a Bcrp substrate with age. Nitrofurantoin (NTF) is a good substrate for Bcrp and was used as model substance. Brain-to-plasma concentration ratio (Kp) of NTF was measured at postnatal Day 1, Day 4, Day 11 and in adult rats. Microdialysis was used to measure concentration ratio of unbound NTF across the BBB (Kp,uu) with or without blockers for active transport (PSC833 and probenecid). To investigate the in vivo contribution of Bcrp, Kp was also measured in Bcrp-/- and wild-type control mice with or without the selective Bcrp blocker Ko143. The Kp decreased with age, but due to an increase in the protein binding. The Kp,uu was on average 0.047 and not affected by the presence of any blocker. Possible explanations for the low Kp,uu is intra-brain metabolism and/or efflux due to other transporter(s). No difference was observed in the Kp of NTF for Bcrp-/- compared to wild-type mice, independent of co-administration with Ko143. Thus, no in vivo contribution of Bcrp to the BBB brain transport of NTF was detected.
Blood-brain barrier, development, active transport, Bcrp, nitrofurantoin, intra-brain metabolism, LC-MS/MS
Research subject Pharmacokinetics and Drug Therapy
IdentifiersURN: urn:nbn:se:uu:diva-109160OAI: oai:DiVA.org:uu-109160DiVA: diva2:249223