Lineweaver–Burk plot and Eadie–Hofstee plot of inhibition of 20-(S)-camptothecin efflux across Caco-2 cells at fixed etoposide concentrations of 0 μM (Δ), 100 μM (•) and 200 μM (□)

Copyright information:Taken from "Membrane transport of camptothecin: facilitation by human P-glycoprotein (ABCB1) and multidrug resistance protein 2 (ABCC2)"BMC Medicine 2004;2():16-16.Published online 4 May 2004PMCID:PMC411064.Copyright © 2004 Lalloo et al; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL. Each point represents the mean (± standard deviation) for at least three observations. The inhibition constant () was determined from a secondary plot (inset) of the slopes of Lineweaver–Burk plots for various inhibitor concentrations. , effective permeability; , initial rate.