Is Ciprofloxacin a Substrate of P‐glycoprotein?

Miki Susanto Park,Hideaki Okochi,Leslie Z Benet

doi:10.1111/j.1753-5174.2010.00032.x

Miki Susanto Park, Hideaki Okochi + Show 1 more

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https://doi.org/10.1111/j.1753-5174.2010.00032.x

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Abstract

IntroductionStudies using MDCKII and LLC-PK1 cells transfected with MDR1 cDNA indicate that ciprofloxacin is not a substrate of P-glycoprotein. However, our data has shown that transport studies done using different P-gp overexpressing cell lines (MDCKI-MDR1, MDCKII-MDR1 and L-MDR1), could lead to contradictory conclusion on whether a compound is a substrate of P-gp. The aim of our study was to determine if ciprofloxacin is indeed not a P-glycoprotein substrate using MDCKI cells transfected with human MDR1 cDNA.MethodsSemi-quantitative RT-PCR was used to determine the mRNA level of MDR1 while Western blot was performed to determine the protein expression level of P-gp, MRP1 and MRP2 in various cells. Ciprofloxacin bidirectional transport studies were performed in MDCKI, MDCKI-MDR1, MDCKII, MDCKII-MDR1, MDCKII-MRP2, LLC-PK1, L-MRP1 and L-MDR1 cells.ResultsCiprofloxacin showed net secretion in MDCKI-MDR1 but net absorption in MDCKI cells. Various P-gp inhibitors decreased the B to A and increased the A to B transport of ciprofloxacin in MDCKI-MDR1 cells while having no effect in MDCKI cells. The B to A transport of ciprofloxacin in MDCKI-MDR1 cells was not affected by non-P-gp inhibitors. In the presence of indomethacin, ciprofloxacin showed net secretion instead of net absorption in MDCKI cells while in the presence of probenecid and sulfinpyrazone, there was no net secretion and absorption. There was no difference in ciprofloxacin transport between MDCKII and MDCKII-MDR1, LLC-PK1 and L-MDR1, LLC-PK1 and L-MRP1 and MDCKII and MDCKII-MRP2.ConclusionsTransport data in MDCKI and MDCKI-MDR1 cells indicate that ciprofloxacin is a substrate of P-gp but data from MDCKII, MDCKII-MDR1, LLC-PK1 and L-MDR1 cells indicate that ciprofloxacin is not a substrate of P-gp. Vinblastine, a well-known P-gp substrate, also did not show differences between LLC-PK1 and L-MDR1 cells. Further studies need to be performed to characterize these P-gp overexpressing cell lines and the transport of ciprofloxacin.

Highlights

Studies using MDCKII and LLC-PK1 cells transfected with MDR1 cDNA indicate that ciprofloxacin is not a substrate of P-glycoprotein
Using LLC-PK1 cells transfected with the human MDR1 cDNA (L-MDR1), de Lange et al [7] showed that there was no difference between the apical to basal (A to B) and basal to apical (B to A) transport of ciprofloxacin in L-MDR1 cells
The aim of this study was to determine whether ciprofloxacin is not a P-gp substrate using MDCKI cells transfected with human MDR1 cDNA (MDCKI-MDR1) [10]

Summary

Introduction

Studies using MDCKII and LLC-PK1 cells transfected with MDR1 cDNA indicate that ciprofloxacin is not a substrate of P-glycoprotein. Our data has shown that transport studies done using different P-gp overexpressing cell lines (MDCKI-MDR1, MDCKII-MDR1 and L-MDR1), could lead to contradictory conclusion on whether a compound is a substrate of P-gp. The aim of our study was to determine if ciprofloxacin is not a P-glycoprotein substrate using MDCKI cells transfected with human MDR1 cDNA. Ciprofloxacin bidirectional transport studies were performed in MDCKI, MDCKI-MDR1, MDCKII, MDCKII-MDR1, MDCKII-MRP2, LLC-PK1, L-MRP1 and L-MDR1 cells. Using LLC-PK1 cells transfected with the human MDR1 cDNA (L-MDR1), de Lange et al [7] showed that there was no difference between the apical to basal (A to B) and basal to apical (B to A) transport of ciprofloxacin in L-MDR1 cells. Lowes and Simmons [9] showed that there was no net secretion of ciprofloxacin in MDCKII and MDCKIIMDR1 cells, suggesting that ciprofloxacin is not a P-gp substrate

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Results