Modulations of VEGF and iNOS in the rat heart by low level laser therapy are associated with cardioprotection and enhanced angiogenesis

Background and Objectives: It has been shown previously that low-level laser therapy (LLLT) significantly reduces infarct size following induction of myocardial infarction in rats and dogs. The aim of the present study was to investigate the effect of LLLT on the expression of vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS). Study Design and Material and Methods: Myocardial infarction was induced by occlusion of the left descending artery in 87 rats. LLLT was applied to intact and post-infarction. VEGF, iNOS, and angiogenesis were determined. Results: Both the laser-irradiated rat hearts post-infarction and intact hearts demonstrated a significant increase in VEGF and iNOS expression compared to non-laser-irradiated hearts. LLLT also caused a significant elevation in angiogenesis. Conclusions: It is concluded that VEGF and iNOS expression in the infarcted rat heart is markedly upregulated by LLLT and is associated with enhanced angiogenesis and cardioprotection.