Abnormal lymphatic function in kCYC^+/- transgenic mice. (A) Fluorescence microscopy of whole-mounted nontagged ear 5 minutes following intradermal injection of FITC-dextran showing lack of lymphatic drainage in TG mice (left); lymphatics (arrows) are easily visualized in WT mice (right) (× 200). (B) Evans blue dye accumulation in popliteal lymph node (arrow) 10 minutes following dermal injection into footpad is not detected in TG mice (left), whereas the popliteal lymph node is easily visualized in WT mice (right). (C) Quantification (mean ± SD) of Evans blue dye content in popliteal lymph nodes after dermal injection into footpad (n = 8). MRI lymphangiograms showing (D) no thoracic duct enhancement (arrows) 5 and 45 minutes following injection of the dendrimer G8 bilaterally into the midphalangeal areas of TG mice (top row), whereas enhancement is observed in WT mice as early as 5 minutes following injection of G8 (bottom row); (E) delayed detection of the right external iliac node (arrows) in TG (top row), compared to WT (bottom row), mice following injection of the dendrimer G8 bilaterally into the midphalangeal areas; and (F) poor visualization of popliteal lymph nodes (asterisks) and evidence of backflow (arrowheads) in superficial lymphatics of the lower extremities (arrows) in TG (upper), but not WT (lower), mice 15 minutes following G8 injection bilaterally into the midphalangeal areas.