OBJECTIVE: The aim of this study is to evaluate the skin microcirculation increase seen in healthy volunteers after a single exposure to polychromatic visible (pVIS) light, and to prove the role of nitric oxide (NO) in the development of this effect. BACKGROUND DATA: Improvement of microcirculation is one of the most important effects of laser and pVIS light therapy; however, its mechanism of action remains unknown. A main role in the regulation of vascular tone is known to be played by NO. It is produced by NO-synthase (NOS) located in membranes of many cells, including endothelial and blood cells. NOS, a biopteroflavohemoprotein, absorbs pVIS light, resulting in its activation. MATERIALS AND METHODS: The central area of the dorsal side of the right hand (24 cm2) of 42 volunteers was irradiated for 5 min with pVIS light from a Q-light (385-750 nm, 95% polarization, 40 mW/cm2, 12 J/cm2). Then for 90 min, the blood flow rate (Qas) was measured eight times, both in the area of the irradiation (local effect) and in the non-irradiated left hand (systemic effect) by using a high-frequency ultrasound Doppler device, recording Qas in human skin to a depth up to 5 mm. In the central area of the right hand of 14 volunteers an NOS inhibitor, N-monomethyl-L-arginine (L-NMMA, 0.1% solution), was iontophoretically administered prior to exposure, whereas in 10 other subjects it was administered to the left hand with subsequent exposure of the right hand. RESULTS: As soon as 2 min after exposure, Qas in the irradiated area rose on average by 32%, and in 20 min by 45%; it then decreased and in 90 min returned to the initial level. A statistically significant Qas increase in the non-irradiated hand was recorded in 5 min (+9%), and in 20 min it reached a maximum level (+39%), and 90 min later it decreased to the initial values. The presence of L-NMMA in the light-exposed area completely blocked the photoinduced rise of microcirculation, both in the irradiated and in non-irradiated hand; however, its administration to the non-irradiated hand did not prevent these effects. CONCLUSION: The increase in skin microcirculation produced by pVIS light at the local and systemic levels is due to activation of NO synthesis in the irradiated area.
RCT Entities:
OBJECTIVE: The aim of this study is to evaluate the skin microcirculation increase seen in healthy volunteers after a single exposure to polychromatic visible (pVIS) light, and to prove the role of nitric oxide (NO) in the development of this effect. BACKGROUND DATA: Improvement of microcirculation is one of the most important effects of laser and pVIS light therapy; however, its mechanism of action remains unknown. A main role in the regulation of vascular tone is known to be played by NO. It is produced by NO-synthase (NOS) located in membranes of many cells, including endothelial and blood cells. NOS, a biopteroflavohemoprotein, absorbs pVIS light, resulting in its activation. MATERIALS AND METHODS: The central area of the dorsal side of the right hand (24 cm2) of 42 volunteers was irradiated for 5 min with pVIS light from a Q-light (385-750 nm, 95% polarization, 40 mW/cm2, 12 J/cm2). Then for 90 min, the blood flow rate (Qas) was measured eight times, both in the area of the irradiation (local effect) and in the non-irradiated left hand (systemic effect) by using a high-frequency ultrasound Doppler device, recording Qas in human skin to a depth up to 5 mm. In the central area of the right hand of 14 volunteers an NOS inhibitor, N-monomethyl-L-arginine (L-NMMA, 0.1% solution), was iontophoretically administered prior to exposure, whereas in 10 other subjects it was administered to the left hand with subsequent exposure of the right hand. RESULTS: As soon as 2 min after exposure, Qas in the irradiated area rose on average by 32%, and in 20 min by 45%; it then decreased and in 90 min returned to the initial level. A statistically significant Qas increase in the non-irradiated hand was recorded in 5 min (+9%), and in 20 min it reached a maximum level (+39%), and 90 min later it decreased to the initial values. The presence of L-NMMA in the light-exposed area completely blocked the photoinduced rise of microcirculation, both in the irradiated and in non-irradiated hand; however, its administration to the non-irradiated hand did not prevent these effects. CONCLUSION: The increase in skin microcirculation produced by pVIS light at the local and systemic levels is due to activation of NO synthesis in the irradiated area.
Authors: Ana Carolina Araruna Alves; Regiane Albertini; Solange Almeida dos Santos; Ernesto Cesar Pinto Leal-Junior; Eduardo Santana; Andrey Jorge Serra; José Antonio Silva; Paulo de Tarso Camillo de Carvalho Journal: Lasers Med Sci Date: 2013-08-29 Impact factor: 3.161
Authors: Tanupriya Agrawal; Gaurav K Gupta; Vikrant Rai; James D Carroll; Michael R Hamblin Journal: Dose Response Date: 2014-09-22 Impact factor: 2.658
Authors: Kelly A Larkin-Kaiser; Paul A Borsa; Harsimran S Baweja; Molly A Moore; Mark D Tillman; Steven Z George; Evangelos A Christou Journal: Lasers Med Sci Date: 2016-06-15 Impact factor: 3.161
Authors: Kelly A Larkin; Jeffrey S Martin; Elizabeth H Zeanah; Jerry M True; Randy W Braith; Paul A Borsa Journal: J Athl Train Date: 2012 Mar-Apr Impact factor: 2.860
Authors: Feng Lin; Steven F Josephs; Doru T Alexandrescu; Famela Ramos; Vladimir Bogin; Vincent Gammill; Constantin A Dasanu; Rosalia De Necochea-Campion; Amit N Patel; Ewa Carrier; David R Koos Journal: J Transl Med Date: 2010-02-16 Impact factor: 5.531