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Evaluation of P‐glycoprotein—Mediated Renal Drug Interactions in an MDR1‐MDCK Model
Author(s) -
Karyekar Chetan S.,
Eddington Natalie D.,
Garimella Tushar S.,
Gubbins Paul O.,
Dowling Thomas C.
Publication year - 2003
Publication title -
pharmacotherapy: the journal of human pharmacology and drug therapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.227
H-Index - 109
eISSN - 1875-9114
pISSN - 0277-0008
DOI - 10.1592/phco.23.4.436.32125
Subject(s) - cimetidine , p glycoprotein , caco 2 , cell culture , chemistry , secretion , efflux , paracellular transport , pharmacology , in vitro , kidney , permeability (electromagnetism) , medicine , endocrinology , biology , biochemistry , multiple drug resistance , genetics , membrane , antibiotics
Study Objective. To evaluate P‐glycoprotein (P‐gp)‐mediated renal drug interactions in an in vitro model of tubular secretion. Design. In vitro experiment. Setting. University‐affiliated pharmacokinetics laboratory. Cell Lines. Madin‐Darby canine kidney (MDCK), multidrug‐resistant‐1 (MDR1)‐MDCK, and human colon carcinoma (Caco‐2) cells. Intervention. Transepithelial transport (basolateral‐to‐apical and apical‐to‐basolateral) of cimetidine was assessed in the absence and presence of various concentrations of the P‐gp inhibitors itraconazole and PSC‐833 in a renal P‐gp cell culture model (MDR1‐MDCK). Measurements and Main Results. Apparent permeability of cimetidine was characterized, and level of P‐gp expression was determined by Western blot analysis, in MDCK (wild type), MDR1‐MDCK, and Caco‐2 cells (for relative comparison). In the presence of PSC‐833, cimetidine's apparent permeability value for basolateral‐to‐apical transport decreased from 2.96 to 1.15 times 10 −6 cm/second, coupled with a decrease in efflux ratio from 2.36 to 1.80. The effect of itraconazole was concentration dependent, with cimetidine's apparent permeability value for basolateral‐to‐apical transport decreasing from 3.96 to 1.92 times 10 −6 cm/second (p<0.05), resulting in a 50% decrease in efflux ratio. Expression of P‐gp was negligible in MDCK (wild‐type) cells, but high‐level expression was confirmed in both MDR1‐MDCK and Caco‐2 cells. Conclusion. P‐glycoprotein plays a significant role in the renal tubular secretion of organic cations such as cimetidine, and the high level of P‐gp expression in MDR1‐MDCK cells makes this a well‐suited model for evaluating mechanisms of renal drug interactions.