Figure 4

Vacuolization and lumen formation during lymphangiogenesis in vivo. Lymphangiogenesis was observed after thermal cauterization of the cornea (A, B) and in lymphangioma (C, D). (A): Prominent pinocytic activity (arrowhead) is visible along the plasma membrane and at cell junction. (B) Endothelial cells (en) containing intracellular vesicles are aligned and surrounded by matrix-free extracellular spaces (*). (C): Aligned elongated endothelial cells surrounded by extracellular spaces. Note the coalescence of intracellular vesicles (cv) and the presence of a blood vessel (bv) containing a white cell. (D) Vesicle coalescence (cv) into an intracellular luminal space is visible through a process similar to that depicted in B. bv = blood vessel; cv = coalescent vesicle; en: endothelial cell. Scale bars: 1 μm.