The role of the efflux transporter P-glycoprotein in brain penetration of prednisolone

in Journal of Endocrinology
Authors:
AM Karssen
Search for other papers by AM Karssen in
Current site
Google Scholar
PubMed
Close
,
OC Meijer
Search for other papers by OC Meijer in
Current site
Google Scholar
PubMed
Close
,
IC van der Sandt
Search for other papers by IC van der Sandt in
Current site
Google Scholar
PubMed
Close
,
AG De Boer
Search for other papers by AG De Boer in
Current site
Google Scholar
PubMed
Close
,
EC De Lange
Search for other papers by EC De Lange in
Current site
Google Scholar
PubMed
Close
, and
ER De Kloet
Search for other papers by ER De Kloet in
Current site
Google Scholar
PubMed
Close
Free access

Sign up for journal news

In the present study, we have investigated the role of the multidrug resistance (mdr) P-glycoprotein (Pgp) at the blood-brain barrier in hampering the access of the synthetic glucocorticoid, prednisolone. In vivo, a tracer dose of [(3)H]prednisolone poorly penetrated the brain of adrenalectomised wild-type mice, but the uptake was more than threefold enhanced in the absence of Pgp expression in mdr1a (-/-) mice. In vitro, in stably transfected LLC-PK1 monolayers the human MDR1 P-glycoprotein was able to transport prednisolone present at a micromolar concentration. A specific Pgp blocker, LY 335979, could block this polar transport of [(3)H]prednisolone. Human Pgp does not transport all steroids, as cortexolone was not transported at all and aldosterone was only weakly transported. The ability of Pgp to export the synthetic glucocorticoid, prednisolone, suggests that uptake of prednisolone in the human brain is impaired, leading to a discrepancy between central and peripheral actions. Furthermore, the ensuing imbalance in activation of the two types of brain corticosteroid receptors may have consequences for cognitive performance and mood.

 

  • Collapse
  • Expand