RT Journal Article SR Electronic T1 Functional Induction of P-glycoprotein in the Blood-Brain Barrier of Streptozotocin-Induced Diabetic Rats: Evidence for the Involvement of Nuclear Factor-κB, a Nitrosative Stress-Sensitive Transcription Factor, in the Regulation JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 1996 OP 2005 DO 10.1124/dmd.107.015800 VO 35 IS 11 A1 Han-Joo Maeng A1 Mi-Hwa Kim A1 Hyo-Eon Jin A1 Sang Mi Shin A1 Takasi Tsuruo A1 Sang Geon Kim A1 Dae-Duk Kim A1 Chang-Koo Shim A1 Suk-Jae Chung YR 2007 UL http://dmd.aspetjournals.org/content/35/11/1996.abstract AB The objective of this study was to investigate the transport kinetics of cyclosporin A, a well known substrate for P-glycoprotein (P-gp), across the blood-brain barrier (BBB), and the expression of the transporter in the brain of streptozotocin-induced diabetic rats. The in vivo transport clearance of cyclosporin A was significantly reduced in diabetic rats compared with that in the control. The decreased transport was associated with the increased level of mRNA and the protein for P-glycoprotein in the rat brain. The functional activity of the efflux transporter in mouse brain capillary endothelial (MBEC4) cells, an in vitro model of the BBB, was also stimulated when slow nitric oxide (NO)-releasing donors were present, whereas the stimulation was absent in the case of rapid NO-releasing donors (e.g., S-nitroso-N-acetyl-dl-penicillamine and diethylenetriamine). The stimulatory effect was highest for sodium nitroprusside (SNP) and the functional induction associated with the increased mRNA and protein level of the transporter. The pretreatment of the cell with SNP along with ascorbate, methylene blue, or superoxide dismutase attenuated the induction of function and expression for P-glycoprotein, suggesting that the reaction product between superoxide and NO is involved in the induction of function and expression. The level of nuclear translocation of nuclear factor-κB (NF-κB) and DNA binding activity of nuclear extracts to the NF-κB consensus oligonucleotide was increased in MBEC4 cells pretreated with SNP. Taken together, these observations suggest that nitrosative stress leads to the up-regulation of the message for the efflux transporter and, ultimately, to the enhanced function, probably via a NF-κB-dependent mechanism. The American Society for Pharmacology and Experimental Therapeutics