Figure 4. Impaired collecting lymphatic vessel function and reduced spread of tracer in dermal lymphatic vessels after 17 weeks of HFD in K14-VEGF-C mice.

NIR-imaging was performed after intradermal injection of 5 μL of 25 μM P20D680. Normal (A) and irregular (B) contraction patterns in chow and HFD mice, respectively. Linear regression analysis (C) shows a significant negative correlation between weight and contraction frequencies. High (D) and low (E) spreading of tracer within dermal lymphatic vessels in chow and HFD fed mice, respectively, after 15 minutes of imaging. Scale bars  =  2 mm. Quantification (F) shows lower percentage of tracer-perfused lymphatic vessels of the skin in the lower limb of mice on HFD as compared to chow diet. *P≤0.05.