Effect of venous ulcer exudates on angiogenesis in vitro.
BACKGROUND
Angiogenesis, the formation of new from existing capillaries, is an important mechanism in venous ulcer healing. The aim of this study was to determine whether venous leg ulcer wound exudates stimulate or inhibit angiogenesis.


METHODS
Fluid exudate was obtained from 16 venous ulcers over a 4-h interval. Five of the ulcers had not healed after more than 1 year of compression bandaging, and five were rapidly healing ulcers. As a control, acute wound fluids were collected from subcutaneous drains in seven patients. Vascular endothelial growth factor (VEGF) at 2 ng/ml acted as a positive control. Tubules stained with an antiendothelial antibody were quantified using an image analysis system. The extent of angiogenesis was expressed as the ratio of the mean tubule length in the test wells over that in blank control wells.


RESULTS
Venous ulcer exudates significantly inhibited angiogenesis (mean (95 per cent confidence interval) 0.72 (0.48 to 0.96)) compared with acute wound fluids (2.48 (0.86 to 4.10)) (P < 0.002) and VEGF (1.47 (1.32 to 1.61)) (P = 0.01). Exudates from the five non-healing venous ulcers inhibited angiogenesis (0.31 (0.15 to 0.46)) significantly more than exudates from the five rapidly healing venous ulcers (0.93 (0.21 to 1.65)) (P = 0.03).


CONCLUSIONS
Fluid exudate from venous ulcers, in particular those that healed slowly, inhibited experimental angiogenesis in this study.
Drinkwater
S L
SL
Department of Academic Surgery, First Floor, North Wing, St Thomas' Hospital, Lambeth Palace Road, London SE1 7EH, UK.
Smith
A
A
Sawyer
B M
BM
Burnand
K G
KG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000502:physiology; D016228:Endothelial Growth Factors / Q000378:metabolism; D005122:Exudates and Transudates / Q000502:physiology*; D005260:Female; D006801:Humans; D008222:Lymphokines / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000503:physiopathology*; D014647:Varicose Ulcer / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D014945:Wound Healing / Q000502:physiology
D020533:Angiogenesis Inhibitors; D016228:Endothelial Growth Factors; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors