查看文章

In 1976, Juliano and Ling¹ reported expression of a 170 kDa protein in colchicine‐resistant Chinese hamster ovary (CHO) cells that was absent in drug‐sensitive cells. Because this protein altered cellular permeability to colchicine, the authors named it P‐glycoprotein (P‐gp).¹ P‐gp overexpression was described in tumor samples and leukemic cells.² High homology with bacterial transporters suggested that P‐gp was an efflux transporter, modulating intracellular xenobiotic concentrations.³ In 1986, the gene encoding P‐gp was discovered and designated MDR1 (HUGO name ABCB1).⁴ Immunohistochemical studies demonstrated P‐gp expression in tissues with secretory or excretory functions (liver, kidney, and gastrointestinal tract) and at blood‐tissue barrier sites, such as the blood‐brain barrier.⁵ This pattern of expression indicated that P‐gp may influence xenobiotic response and toxicity, either through …