Fig. 3

Decreased lymphatic clearance in tumor necrosis factor–transgenic (TNF-Tg) mice is associated with the progression of arthritis. Indocyanine green ([ICG] 0.1 mg/ml in 6 μl) was injected intradermally into the footpads of 1-, 2.5-, and 5-month-old TNF-Tg mice and their wild-type (WT) littermates. Lymphatic vessels of the entire leg were examined using near-infrared ICG imaging immediately and at 6 and 24 h post-ICG administration. The ICG fluorescence signal intensity at the footpads (outlined by the red circles) was recorded. The ICG clearance was calculated. Shown are a representative ICG signal (a) and the percentage of ICG clearance (b). Values are mean ± standard deviation of four or five mice. *p < 0.05 vs. WT mice