Endocrine Abstracts

In rodents synthetic glucocorticoids such as e.g. dexamethasone poorly penetrate the blood brain barrier because of multidrug resistance P-glycoprotein (mdr-Pgp). Also cortisol, not naturally occurring in rats and mice, is hampered in uptake. The evidence for this role of the efflux transporter was substantiated with the mdr1a knock out mice. 3H- cortisol and 3H-dexamethasone administered to the mdr1a mutants did label brain targets that retained the ster...