Gd. Phillips et al., TRANSFORMING GROWTH-FACTOR-BETA (TGF-B) STIMULATION OF ANGIOGENESIS -AN ELECTRON-MICROSCOPIC STUDY, Journal of submicroscopic cytology and pathology, 25(2), 1993, pp. 149-155
The object of this study was to examine the initiation and pattern of
corneal angiogenesis stimulated by transforming growth factor beta (TG
F-B) using scanning electron microscopy (SEM) of vascular corrosion ca
sts and transmission electron microscopy (TEM). Fifty nanograms of TGF
-B was combined with the slow release polymer Hydron and implanted in
the rabbit cornea as an assay for angiogenic activity. Two and 7 days
after implantation, the corneas were removed for TEM. At the same time
intervals the limbal vasculature was filled with Mercox, an acrylic m
onomer. After the Mercox hardened, the tissue was digested with altern
ating immersions in 40% KOH and distilled water. The resulting casts w
ere air-dried, sputter coated with gold and viewed with the scanning e
lectron microscope. TEM revealed that 2 days after implantation, TGR-B
elicited an influx of a vast number of inflammatory cells, which at t
wo days were predominantly neutrophils. By 7 days the inflammation had
subsided and typical capillaries were seen between the collagenous la
mine of the normally avascular corneal stroma. SEM of vascular corrosi
on casts showed evidence of margination/diapedesis of leukocytes from
the limbal venules 2 days post-implantation. In addition, the casts fr
om the 7 day time point showed that new vessels arose solely from limb
al venules.