Fig. 1.

FGF-2 stimulates corneal lymphangiogenesis. (A) In the traditional corneal assay, 80 ng of FGF-2 (P) stimulates blood vessel growth from the peripheral limbal vasculature (arrowhead). (B) The traditional assay is viewed under fluorescent microscopy after labeling blood vessels yellow–green and lymphatic vessels red (arrowhead). Sucralfate in the FGF-2 pellet (P) autofluoresces green. (C) At the opposite end of the cornea, only lymphatic vessels (arrows) sprout. (Inset) Limbal vessels in the control cornea. (D) Lowering the dose of FGF-2 pellet to 12.5 ng (P) and moving it farther from the limbus results in less angiogenesis, but lymphatic vessels still reach the pellet. (E) Corneal lymphatic vessels were morphologically different from blood vessels. In addition, corneal lymphatic vessels did not express CD34 (F) or Tie2 (G and H, arrowheads) but did express VEGFR-3 (I). (Scale bars, 0.5 mm in B–D, 50 μmin E and I, and 200 μmin F–H.)