Proceedings Article | 28 February 2006
KEYWORDS: In vitro testing, Laser irradiation, Laser therapeutics, Tissues, Blood, Collagen, Stem cells, In vivo imaging, Laser tissue interaction, NOx
One of the feasible explanations for long-term treatment effects of laser therapy of diseases connected with tissue ischemia and altered blood circulation is activation of angiogenesis after low level laser irradiation.
The aim of the current study was to investigate if laser irradiation can enhance vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (FGF) induced angiogenesis in vitro. The study was conducted on rat thoracic aortal rings. Samples of group 1 served as control, samples of groups 2 and 3 were incubated with VEGF or FGF, group 4 samples were irradiated with laser (660 nm, 20 mW) during 10 min, samples of groups 5 and 6 were incubated with VEGF or FGF accordingly and received 10 min of laser irradiation.
In the control group no noticeable angiogenesis occurred. The application of VEGF activated angiogenesis: the area covered by new vessels was 1,3±0,24 mm2 and the maximal length of vessels was 0,93±0,11 mm. Laser light irradiation (group 4) activated angiogenesis (1,9±0,29 mm2 and 0,75±0,10 mm). The combined influence of laser light and VEGF on angiogenesis (group 5) was significantly stronger (p <0,001), than each of the factors separately (6,98±0,88 mm2 and 1,7±0,23 mm).
Application of FGF also activated angiogenesis: the area covered by new vessels was 2,76±0,22 mm2 and the maximal length of vessels was 1,19±0,12 mm. Combined influence of laser light and FGF on angiogenesis (group 6) was again significantly stronger (p <0,001), than each of the factors separately (5,43±0,28 mm2 and 1,99±0,10 mm). Studies show that laser irradiation can intensify effects of growth factors in vitro.
