کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1960333 | 1057956 | 2014 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Kinetic Analysis of Rhodamines Efflux Mediated by the Multidrug Resistance Protein (MRP1) Kinetic Analysis of Rhodamines Efflux Mediated by the Multidrug Resistance Protein (MRP1)](/preview/png/1960333.png)
Characterization of rhodamine 123 as functional assay for MDR has been primarily focused on P-glycoprotein-mediated MDR. Several studies have suggested that Rh123 is also a substrate for MRP1. However, no quantitative studies of the MRP1-mediated efflux of rhodamines have, up to now, been performed. Measurement of the kinetic characteristics of substrate transport is a powerful approach to enhancing our understanding of their function and mechanism. In the present study, we have used a continuous fluorescence assay with four rhodamine dyes (rhodamine 6G, tetramethylrosamine, tetramethylrhodamine ethyl ester, and tetramethylrhodamine methyl ester) to quantify drug transport by MRP1 in living GLC4/ADR cells. The formation of a substrate concentration gradient was observed. MRP1-mediated transport of rhodamine was glutathione-dependent. The kinetics parameter, ka = VM/km, was very similar for the four rhodamine analogs but ∼10-fold less than the values of the same parameter determined previously for the MRP1-mediated efflux of anthracycline. The findings presented here are the first to show quantitative information about the kinetics parameters for MRP1-mediated efflux of rhodamine dyes.
Journal: - Volume 85, Issue 3, September 2003, Pages 2006–2014