Fig. 4.

Lymphatic morphology changes during edema. (A) Normal tissue showed few proliferating cells and small superficial lymphatics (gold arrowheads) with the underlying collecting lymphatic vessels (white arrowheads). PCNA staining (red) indicated that as the tail volume increased, lymphatic endothelial cells (LECs, green) proliferated (white arrows). At day 10, LECs in the vessels were proliferating and the vessels were hyperplastic. This LEC proliferation was reduced at 20 days and absent at 30 days. Edema also induced the proliferation of other cells in the dermis (gold arrows). (B) Confocal microscopy of the dermal lymphatic vessels demonstrated the drastic hyperplasia and morphological changes associated with edema at 7 and 14 days, with an abnormal morphology still present at 30 days. Scale bars=100 μm. (C) The number of LECs per lymphatic structure was greatest at day 7 in both wild-type and MMP-9 deficient mice (*P<0.05 over control). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)