1. Functional Characterization of a High-Affinity Choline Transport System in Human Keratinocytes 
Kathrin Hoffmann, Franziska Grafe, Wolfgang Wohlrab, Reinhard H. Neubert, Matthias Brandsch, Dr. 
Journal of Investigative Dermatology 
Volume 119, Issue 1, Pages (July 2002)
DOI: /j x
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

2. Figure 1
Time course of [3H]choline uptake in HaCaT cells. Uptake of [3H]choline (3 nM) was measured in buffer (pH 7.5) containing NaCl 140 mM (closed circles) or LiCl 140 mM (open circles). Data are shown as mean ± SEM, n ≥ 4.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

3. Figure 2
Effect of pH on [3H]choline uptake in HaCaT cells. Uptake of [3H]choline (3 nM) was measured in buffer with different pH values containing NaCl 140 mM for 10 min. Data are shown as mean ± SEM, n ≥ 4.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

4. Figure 3
Saturation kinetics of choline uptake in HaCaT cells. Uptake of [3H]choline (3 nM) in presence of increasing concentrations of unlabeled choline was measured at pH 7.5 for 10 min. The results are shown as mean ± SEM, n ≥ 4, after subtraction of the nonmediated component of transport ([3H]choline uptake in presence of 20 mM unlabeled choline). Inset: Eadie-Hofstee plot.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

5. Figure 4
Substrate specificity of [3H]choline uptake in HaCaT cells. Uptake was measured at pH 7.5 for 10 min. Concentration of inhibitors was 1 mM. Data are shown as mean ± SEM, n = 4.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

6. Figure 5
Dose–response relationship for the inhibition of [3H]choline uptake by various organic cations in HaCaT cells. Uptake of [3H]choline (3 nM) was measured in the absence (control) or presence of increasing concentrations of various organic cations at pH 7.5 for 10 min. The results are shown as mean ± SEM, n ≥ 4.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

7. Figure 6
Substrate specificity of choline uptake in normal keratinocytes. Uptake of [3H]choline was measured in the presence of various organic cations (1 mM) at pH 7.5 for 10 min. The results are shown as mean ± SEM, n ≥ 4.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions