Corrigendum to "Low-Level Laser Irradiation Exerts Antiaggregative Effect on Human Platelets Independently on the Nitric Oxide Metabolism and Release of Platelet Activation Markers".

[This corrects the article DOI: 10.1155/2017/6201797.].

Effect of endovascular coronary low-level laser therapy during angioplasty on the release of endothelin-1 and nitric oxide.

BACKGROUND: Nitric oxide (NO) and endothelin-1 are potentially significant factors contributing to the pathogenesis of post-angioplasty restenosis. It may be postulated that low-level laser therapy (LLLT) can favorably influence the process of restenosis by affecting those factors. OBJECTIVES: The aim of the study was to evaluate the effect of LLLT applied during percutaneous coronary intervention (PCI) on the factors participating in the homeostasis of vascular tone - NO and endothelin-1. MATERIAL AND METHODS: In a randomized, prospective study of 52 subjects undergoing PCI, an additional 808 nm intravascular LLLT was applied at a dose of 9 J/cm2 in the lesion part. The control group was 49 subjects with PCI only. We assessed the concentration of nitrites/nitrates reflecting NO metabolism as well as endothelin-1 in both groups before PCI, and at 6 h, 12 h and 1 month after the procedure. In addition, half a year after PCI, a follow-up angiography was performed. RESULTS: Statistically higher nitrite/nitrate concentrations were observed in the laser group as compared to the control group in all tests except the pre-PCI assays. Endothelin-1 levels were significantly higher in the laser group 6 h after PCI with a significant decrease in subsequent tests, which was not observed in the control group. The restenosis rate was 15.0% in the laser group and 32.4% in the control group (however the difference was not statistically significant). CONCLUSIONS: LLLT applied during the PCI procedure can influence the process of restenosis by modifying NO and endothelin-1 concentrations.

Low-Level Laser Irradiation Exerts Antiaggregative Effect on Human Platelets Independently on the Nitric Oxide Metabolism and Release of Platelet Activation Markers.

AIM: The goal of the study is to develop a model allowing to investigate precisely the effect of low-level laser therapy (LLLT) on platelet aggregation and to verify the hypothesis regarding the role of the nitric oxide (NO) bioavailability and platelet activation markers in modulating platelet aggregation. METHODS: A total of 41 healthy volunteers at the age of 21-45 years were investigated. At first, platelet aggregation in response to three agonists (TRAP, ADP, and collagen) was evaluated following previous exposure to different doses of laser radiation (λ = 662 nm) to assess the dose-response effect. Subsequently, plasma levels of platelet activation markers (PF4-platelet factor-4 and sP-selectin) as well as the substrate for nitric oxide synthase, L-arginine, and its competitive inhibitors (ADMA-asymmetric dimethylarginine and SDMA-symmetric dimethylarginine) were measured. RESULTS: All doses of laser irradiation significantly reduced the aggregation. However, the most pronounced effect was observed for 19.7 J/cm2. No significant differences in the levels of platelet activation markers nor in the nitric-oxide-metabolic-pathway compounds between analyzed groups were noted. CONCLUSIONS: We have demonstrated in the established in vitro experimental model that the LLLT in a reproducible manner decreases the whole blood platelet aggregation regardless of the NO bioavailability or changes in the platelet activation markers.

Effect of the transdermal low-level laser therapy on endothelial function.

The effect of low-level laser therapy (LLLT) on the cardiovascular system is not fully established. Since the endothelium is an important endocrine element, establishing the mechanisms of LLLT action is an important issue.The aim of the study was to evaluate the effect of transdermal LLLT on endothelial function.In this study, healthy volunteers (n = 40, age = 20-40 years) were enrolled. N = 30 (14 female, 16 male, mean age 30 ± 5 years) constituted the laser-irradiated group (LG). The remaining 10 subjects (6 women, 4 men, mean age 28 ± 5 years) constituted the control group (CG). Participants were subjected to LLLT once a day for three consecutive days. Blood for biochemical assessments was drawn before the first irradiation and 24 h after the last session. In the LG, transdermal illumination of radial artery was conducted (a semiconductor laser λ = 808 nm, irradiation 50 mW, energy density 1.6 W/cm(2) and a dose 20 J/day, a total dose of 60 J). Biochemical parameters (reflecting angiogenesis: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), angiostatin; antioxidative status: glutathione (GSH) and the nitric oxide metabolic pathway: symmetric dimethylarginine (SDMA), asymmetric dimethylarginine (ADMA) and L-arginine) were assessed. In the LG, a significant increase in GSH levels and considerable decrease in angiostatin concentration following the LLLT were observed. No significant differences in levels of the VEGF, FGF, SDMA, ADMA were observed.LLLT modifies vascular endothelial function by increasing its antioxidant and angiogenic potential. We found no significant differences in levels of the nitric oxide pathway metabolites within 24 h following the LLLT irradiation.

Effects of intravascular low-level laser therapy during coronary intervention on selected growth factors levels.

OBJECTIVE: The objective of this study was to evaluate the effect of intravascular low-level laser therapy (LLLT) on selected growth factor levels in subjects undergoing percutaneous coronary interventions (PCI). BACKGROUND DATA: Restenosis remains the main problem with the long-term efficacy of PCI, and growth factors are postulated to play a crucial role in the restenosis cascade. MATERIALS AND METHODS: In a randomized prospective study, an 808 nm LLLT (100 mW/cm2, continuous wave laser, 9 J/cm2, illuminated area 1.6-2.5 cm2) was delivered intracoronarily to patients during PCI. Fifty-two patients underwent irradiation with laser light, and 49 constituted the control group. In all individuals, serum levels of insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), transforming growth factor-ß1 (TGF-ß1), and fibroblast growth factor-2 (FGF-2) were measured before angioplasty, then 6 and 12 h and 1 month after the procedure. In all patients, a control angiography was performed 6 months later. RESULTS: There were no significant differences in IGF-1 and VEGF levels between the groups. While evaluating FGF-2, we observed its significantly lower levels in the irradiated patients during each examination. There was a significant increase in TGF-ß1 level in control group after 12 h of observation. In the irradiated individuals, control angiography revealed smaller late lumen loss and smaller late lumen loss index as compared with the control group. The restenosis rate was 15.0% in the treated group, and 32.4% in the control group, respectively. CONCLUSIONS: LLLT decreases levels of TGF-ß1 and FGF-2 in patients undergoing coronary intervention, which may explain smaller neointima formation.