OBJECTIVE: The aim of the present study was to determine whether the plasma membrane is also involved in the light-tissue interaction because of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase electron chain, which can serve as a photosensitizer. BACKGROUND DATA: It has been suggested that the mechanism of photobiostimulation involves light-induced low levels of reactive oxygen species (ROS) that serve as signal transduction messengers. Production of ROS following visible-light irradiation was verified by the electron paramagnetic resonance (EPR) spin-trapping technique, and the mitochondrial cytochromes were suggested as the main cellular target for visible-light absorption. METHODS: Isolated sperm membranes were illuminated with visible light and the increase in oxygen radical production was measured using the EPR spin-trapping technique coupled with the probe 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). A broadband visible light source (400-800 nm) at 40-130 mW/cm(2) with appropriate filters provided the illumination. In order to determine whether the light-induced ROS production is a result of a photo-accelerated electron transfer in the enzyme-catalyzed reaction with oxygen in the plasma membrane, or resulted from a photochemical reaction of the chromophores alone with oxygen, denatured membranes were irradiated as well. RESULTS: Visible-light-induced oxyradicals were detected in isolated sperm membranes. Blue light was found to be more effective than red. Illuminated denatured membranes produced the same amount of ROS as non-denatured membranes. CONCLUSIONS: Visible-light illumination, especially in the blue region, increases ROS levels in isolated plasma membranes. The mechanism of ROS formation is probably a photochemical reaction of the membranal chromophhores, for example, cytochromes or flavins with oxygen, and not an enzyme-catalyzed photochemical reaction.
OBJECTIVE: The aim of the present study was to determine whether the plasma membrane is also involved in the light-tissue interaction because of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase electron chain, which can serve as a photosensitizer. BACKGROUND DATA: It has been suggested that the mechanism of photobiostimulation involves light-induced low levels of reactive oxygen species (ROS) that serve as signal transduction messengers. Production of ROS following visible-light irradiation was verified by the electron paramagnetic resonance (EPR) spin-trapping technique, and the mitochondrial cytochromes were suggested as the main cellular target for visible-light absorption. METHODS: Isolated sperm membranes were illuminated with visible light and the increase in oxygen radical production was measured using the EPR spin-trapping technique coupled with the probe 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). A broadband visible light source (400-800 nm) at 40-130 mW/cm(2) with appropriate filters provided the illumination. In order to determine whether the light-induced ROS production is a result of a photo-accelerated electron transfer in the enzyme-catalyzed reaction with oxygen in the plasma membrane, or resulted from a photochemical reaction of the chromophores alone with oxygen, denatured membranes were irradiated as well. RESULTS: Visible-light-induced oxyradicals were detected in isolated sperm membranes. Blue light was found to be more effective than red. Illuminated denatured membranes produced the same amount of ROS as non-denatured membranes. CONCLUSIONS: Visible-light illumination, especially in the blue region, increases ROS levels in isolated plasma membranes. The mechanism of ROS formation is probably a photochemical reaction of the membranal chromophhores, for example, cytochromes or flavins with oxygen, and not an enzyme-catalyzed photochemical reaction.
Authors: Adriano F P Siqueira; Fernanda S Maria; Camilla M Mendes; Thais R S Hamilton; Andressa Dalmazzo; Thiago R Dreyer; Herculano M da Silva; Marcilio Nichi; Marcella P Milazzotto; José A Visintin; Mayra E O A Assumpção Journal: Lasers Med Sci Date: 2016-06-07 Impact factor: 3.161
Authors: Hannah Serrage; Vladimir Heiskanen; William M Palin; Paul R Cooper; Michael R Milward; Mohammed Hadis; Michael R Hamblin Journal: Photochem Photobiol Sci Date: 2019-06-11 Impact factor: 3.982
Authors: József Bódis; Krisztina Gödöny; Ákos Várnagy; Kálmán Kovács; Miklós Koppán; Bernadett Nagy; János Erostyák; Róbert Herczeg; Julia Szekeres-Barthó; Attila Gyenesei; Gabor L Kovács Journal: Med Princ Pract Date: 2020-05-29 Impact factor: 1.927