Figure 5: Quantification of lymphatic contraction frequency (a, b) and fluorescence signal amplitude in lymphatic contractions (c, d) in the skin with or without pigmentation, fed a regular ((a), (c); ) or special ((b), (d); ) diet after NIRFI (white) and FRFI (black). Data are shown as mean ± SEM. Paired and unpaired Student T-tests were performed in (c). Mann–Whitney and Wilcoxon tests were used to compare two unpaired or paired groups, respectively, in (d). . . . NS, not significant ().