Faculty Member Islamic Azad University- Tabriz Branch Tabriz, Azarbayjan-e Sharqi, Iran
Background: The healthy endothelial cells are essential for maintenance of vascular homeostasis involving antioxidant, anti-inflammatory, pro- fibrinolytic, anti-adhesive, or anticoagulant effects. Oppositely, endothelial dysfunction is primarily characterized by impaired regulation of vascular tone as a result of reduced endothelial nitric oxide (NO) synthase activity, lack of cofactors for NO synthesis, attenuated NO release, or increased NO degradation. As is well recognized, the majority of atherosclerosis start with a vascular injury, resulting in endothelial dysfunction.
Aims: In this study, we aimed to investigate photobiomodulation therapy on endothelial function in the rabbit carotid artery injury model.
Methods: Briefly, New Zealand white rabbits underwent balloon dilatation injury at the right common carotid artery. After 2 days, common carotid arteries of the treatment group at lesion region, treated using extracorporeal low- level near- infrared laser (850 nm, 500mw, 100 J/cm2)- mediated photobiomodulation therapy. In order to evaluate endothelial-dependent relaxation, acetylcholine-mediated dilation (AMD) was measured during the infusion of acetylcholine at a rate of 0.5 µg/kg/min and endothelial independent relaxation was evaluated by measuring nitroglycerin mediated dilation (NMD) during the infusion of nitroglycerin at a rate of 5 µg/kg/min.
Results: Results from B-mode ultrasound images showed significant differences in AMD between the treated and the non- treated rabbits (p < 0.05), whereas there were no significant differences in NMD between the treatment and normal groups (p>0.05). No microscopic intimal lesions were seen in the normal and treated rabbits, but intimal thickening was observed in the histological studies in the non-treated rabbits.
Conclusion(s): Low- level near- infrared laser- mediated photobiomodulation therapy can cause to improve endothelial dysfunction via increasing endothelial nitric oxide (NO) synthase. This protocol may be a potential treatment to endothelial dysfunction after balloon angioplasty.
