P-glycoprotein as the drug efflux pump in primary cultured bovine brain capillary endothelial cells

Life Sci. 1992;51(18):1427-37. doi: 10.1016/0024-3205(92)90537-y.


The expression of a functional P-glycoprotein (P-gp) which pumps drugs out of brain capillary endothelial cells (BCEC) into blood was studied by evaluating the steady-state uptake and efflux of vincristine (VCR) by primary cultured bovine BCEC. The steady-state uptake of VCR was increased in the presence of metabolic inhibitors, and an anti-P-gp monoclonal antibody, MRK16, as well as verapamil and steroid hormones which are known to reverse multidrug resistance in tumor cells. Furthermore, efflux of VCR from BCEC was inhibited by verapamil. By immunohistochemistry, P-gp was localized at the luminal side of the capillary endothelial cells in both gray matter of bovine brain and primary cultured BCEC. These data suggest that P-gp functions as a drug efflux pump at the luminal side of BCEC and regulates the transfer of certain lipophilic drugs from the blood into the brain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 1
  • Animals
  • Antibodies, Monoclonal
  • Blood-Brain Barrier / physiology*
  • Brain / blood supply*
  • Capillaries / physiology
  • Carrier Proteins / physiology*
  • Cattle
  • Cells, Cultured
  • Drug Resistance / physiology
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / physiology*
  • Membrane Glycoproteins / physiology*
  • Vincristine / pharmacokinetics


  • ATP Binding Cassette Transporter, Subfamily B, Member 1
  • Antibodies, Monoclonal
  • Carrier Proteins
  • Membrane Glycoproteins
  • Vincristine