Figure 5.

[¹⁸F]-D4-FCHP featured as a preferable substrate for the efflux system. (A) The standard 1-h ¹⁸F-D4-FCH uptake assay for cells pretreated with CoCl₂ for 24 h. The Cys A-treated cells were pre-treated with 10 µM cys A for 24 h and then incubated with cys A and 0.37 MBq [¹⁸F]-D4-FCH for 1 h. Three independent sets of six repeats for each condition (n = 18) were carried out. A two-way ANOVA with Tukey’s multiple comparison tests were carried out. (B) A summary of the radiolabelled choline species. The dominant radiolabelled choline species [¹⁸F]-D4-FCH] determines the [¹⁸F]-D4-FCH uptake. The cells were pretreated with 10 µM CK2, 200 µM CoCl₂, or 10 µM cys A for 24 h and then incubated with 0.37 MBq [¹⁸F]-D4-FCH for 1 h. The data are the mean ± standard deviation for three independent repeats (n = 3). A one-way ANOVA with Tukey’s multiple comparison tests were carried out.