TY - JOUR T1 - THE SIGNAL TRANSDUCTION PATHWAYS INVOLVED IN HEPATIC CYTOCHROME P450 REGULATION IN THE RAT DURING A LIPOPOLYSACCHARIDE-INDUCED MODEL OF CENTRAL NERVOUS SYSTEM INFLAMMATION JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 1521 LP - 1531 DO - 10.1124/dmd.105.004564 VL - 33 IS - 10 AU - Dalya Abdulla AU - Kerry B. Goralski AU - Elena Garcia Del Busto Cano AU - Kenneth W. Renton Y1 - 2005/10/01 UR - http://dmd.aspetjournals.org/content/33/10/1521.abstract N2 - It is well known that inflammatory and infectious conditions of the central nervous system (CNS) differentially regulate hepatic drug metabolism through changes in cytochrome P450 (P450); however, the pathways leading to this regulation remain unknown. We provide evidence delineating a signal transduction pathway for hepatic P450 gene expression down-regulation in an established rat model of CNS inflammation using lipopolysaccharide (LPS) injected (i.c.v.) directly into the lateral cerebral ventricle. Brain cytokine levels were elevated, and the expression of tumor necrosis factor α and inhibitor of κB alpha (IκBα) were increased in the liver following the i.c.v. administration of LPS, indicating the presence of an inflammatory response in the brain and liver. The expression of CYP2D1/5, CYP2B1/2, and CYP1A1 was down-regulated following CNS inflammation. The binding of several transcription factors [nuclear factor of the κ enhancer in B cells (NF-κB), activator protein-1, cAMP response element binding protein, CCAAT-enhancer binding protein (C/EBP)] to responsive elements on P450 promoter regions was examined using electromobility shift assays. Binding of both NF-κB and C/EBP to the promoter regions of CYP2D5 and CYP2B1, respectively, was increased, indicating that they play an important role in the regulation of these two isoforms during inflammatory responses. Evidence is also provided suggesting that the rapid transfer of LPS from the CNS into the periphery likely accounts for the down-regulation of P450s in the liver. The American Society for Pharmacology and Experimental Therapeutics ER -