Objectives: since wound healing relies upon angiogenesis (new blood vessel formation) this study assessed the effect of HBO therapy on serum and saliva levels of vascular endothelial growth factor (VEGF) a stimulator of angiogenesis, and Thrombospondin-1 (TSP-1) an inhibitor of angiogenesis, in patients receiving this therapy.
Methods: patients referred for HBO were recruited for this study from the only two hospital based HBO units in Scotland: Ninewells Hospital, Dundee and Aberdeen Royal Infirmary. Tayside and Grampian ethics committee approval was obtained for collecting serum and saliva samples at standardized intervals before, during and at completion of treatment (Ref 256/02 and 03/0029 respectively). Levels of VEGF and TSP-1 were analyzed using R&D systems Quantiglo Human VEGF and Chemicon Chemikine Human TSP-1 ELISA Kits.
Results: it was found in this pilot study that serum VEGF levels decreased significantly p = 0.016 after 10 sessions of HBO therapy. No other statistically significant changes were observed in either VEGF levels in saliva or TSP-1 levels in serum and saliva. There was a considerable variation in both baseline measures and changes after 10 sessions.
Conclusions: since VEGF is stimulated by hypoxia, increased levels of oxygen might be assumed to downregulate VEGF expression. However HBO probably mediates wound healing through a variety of pathways and molecules also involved in the process of angiogenesis such as bFGF, TGF-b, and angiostatin, which also require to be evaluated.