Figure 5.

Angiogenesis and vascular permeability are impaired in epidermal vegf^−/− mice. A: Epidermal KO and WT mice (n = 3 each) were perfused (by tail vein injection) with 1% fluorescein isothiocyanate-albumen in normal saline 40 minutes before biopsy. WT dermis shows increased fluorescence throughout the dermis compared to the KO, suggesting reduced vascular permeability in the KO skin (dotted lines indicate dermo-epidermal junction; arrows indicate surface of SC). B: Fluorescence from samples in A was quantitated by scanning randomized, coded photomicrographs (controlled for equal exposure level) with a Fujifilm luminescent image analyzer (LAS-3000), using incident light and 1/4 second exposures, producing digitized images. The intensity of fluorescence of the papillary dermis from defined areas from four biopsies were measured at ×40 (arbitrary units), and compared statistically (±SEM). C: Six hours after tape stripping, WT mice demonstrate prominent vasodilatation and an increase in factor 8-positive immunostaining of capillaries in the papillary dermis (arrows), whereas KO mice demonstrate no change from basal immunostaining (see Figure 4, A–F).