Role of nitric oxide in the visible light-induced rapid increase of human skin microcirculation at the local and systemic level: I. diabetic patients.

Autor:	Samoilova KA; Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia. samoilova3@yandex.ru, Zhevago NA, Menshutina MA, Grigorieva NB
Jazyk:	angličtina
Zdroj:	Photomedicine and laser surgery [Photomed Laser Surg] 2008 Oct; Vol. 26 (5), pp. 433-42.
DOI:	10.1089/pho.2007.2197
Abstrakt:	Objective: This study aimed to reveal the effects of polychromatic visible (pVIS) or pVIS + near IR (nIR) light similar to some components of solar light on skin microcirculation and microvascular response to the vasodilatators acetylcholine (ACh) and nitroglycerine (NG), in the extremities of patients with diabetic microangiopathy. Background Data: The mechanisms behind light-induced increases in microcirculation as well as extracellular effects of terrestrial pVIS and pVIS + nIR light remain unknown. Materials and Methods: In 24 subjects with type 2 diabetes mellitus local microcirculation was measured in the skin of the foot before and after exposure to both types of light. In another 26 patients systemic microcirculation was studied in the back of the hand before and after exposure of the lumbar-sacral area to light energy. Two different types of light therapy were performed by using two devises: Q-light, which delivers pVIP (385-750 nm) and pVIS nIR light (385-1700 nm) with a power density of 40 mW/cm2, which is similar to summer sunlight at noon in Central Europe. Results: At 2 min after irradiation (12 J/cm2) of the forefoot with pVIS or pVIS + nIR light, a rise in local blood flow volume (Qas) was observed, on average by 39% and 31%, respectively. The maximal effect (+41-47%) had developed in all patients at 30 min, and it then decreased and disappeared completely 24 h post-irradiation. We obtained similar results after irradiation of the sacral area in Qas of the skin of the hand. Both types of microcirculation also increased following a second exposure to the light sources. Enhancement of microcirculation was accompanied by a decrease in the microvascular response to ACh and NG solutions administered intracutaneously by iontophoresis. Conclusion: Both types of irradiation stimulated microcirculation at the local and systemic levels through a mechanism of enhancement of endothelium-dependent and endothelium-independent vasodilation, in which nitric oxide plays a major role.
Databáze:	MEDLINE
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