Abstract
P-glycoprotein (PgP), a drug efflux pump in blood–brain barrier endothelial cells, is a major clinical obstacle for effective central nervous system drug delivery. Identifying PgP regulatory pathways that can be exploited clinically is critical for improving central nervous system drug delivery. We previously found that PgP activity increases in rat brain microvessels concomitant with decreased central nervous system drug delivery in response to acute peripheral inflammatory pain. In the current study, we tested the hypothesis that PgP traffics to the luminal plasma membrane of the microvessel endothelial cells from intracellular stores during peripheral inflammatory pain. Using immunofluorescence microscopy, we detected PgP in endothelial cell nuclei and in the luminal plasma membrane in control animals. Following peripheral inflammatory pain, luminal PgP staining increased while staining in the nucleus decreased. Biochemical analysis of nuclear PgP content confirmed our visual observations. Peripheral inflammatory pain also increased endothelial cell luminal staining of polymerase 1 and transcript release factor/cavin1 and serum deprivation response protein/cavin2, two caveolar scaffold proteins, without changing caveolin1 or protein kinase C delta binding protein/cavin3 location. Our data (a) indicate that PgP traffics from stores in the nucleus to the endothelial cell luminal membrane in response to peripheral inflammatory pain; (b) provide an explanation for our previous observation that peripheral inflammatory pain inhibits central nervous system drug uptake; and (c) suggest a novel regulatory mechanism for PgP activity in rat brain.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.