title: Effect of p-glycoprotein inhibitor combinations on drug efflux from rat brain microvessel endothelial cells.
abstract: In an effort to develop a clinically useful approach to inhibit the drug efflux across the blood brain barrier (BBB) mediated by P-glycoprotein (P-gp), the combined inhibitory effect of four P-gp inhibitors: cyclosporin A (CsA), verapamil (Ver), tetrandrine (Tet) and doxorubicin (Dox), was evaluated by determining the intracellular concentration of rhodamine 123 in in vitro cultured rat brain microvessel endothelial cells (BMEC). The results showed that CsA combined with Ver or Tet synergistically inhibited P-gp mediated efflux of Rh123 from rat BMEC, suggesting that the combined application of P-gp inhibitors would possibly be a useful approach to increase drug concentration in brain tissues, enhance the therapeutic effect and reduce the toxicity of drugs.
authors.affiliation: Department of Pharmacology, China Pharmaceutical University, Jiangsu, PR China.
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Yang
authors.forename: G Q
authors.initials: GQ
authors.lastname: Liu
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors*; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors; D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D044182:Benzylisoquinolines / Q000494:pharmacology; D001812:Blood-Brain Barrier / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002196:Capillaries / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D016572:Cyclosporine / Q000494:pharmacology; D004317:Doxorubicin / Q000494:pharmacology; D004357:Drug Synergism; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D005456:Fluorescent Dyes; D007166:Immunosuppressive Agents / Q000494:pharmacology; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D051381:Rats; D020112:Rhodamine 123; D014700:Verapamil / Q000494:pharmacology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000470:Alkaloids; D000900:Anti-Bacterial Agents; D044182:Benzylisoquinolines; D002121:Calcium Channel Blockers; D005456:Fluorescent Dyes; D007166:Immunosuppressive Agents; D004364:Pharmaceutical Preparations; D020112:Rhodamine 123; C009438:tetrandrine; D004317:Doxorubicin; D016572:Cyclosporine; D014700:Verapamil; D000251:Adenosine Triphosphatases