The plasma membrane is involved in the visible light-tissue interaction.

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.

Red light-induced redox reactions in cells observed with TEMPO.

Objective: The aim of this study was to determine the wavelength dependence of light-induced redox reactions in cells, particularly whether there is any contribution by red wavelengths. An additional aim was to assess the potential of 2,2,6,6-tetramethyl piperidine-N-oxyl (TEMPO) as a tool for measuring these redox reactions.

Background Data: Visible light has been shown to affect cells, and redox reactions, which have been detected previously using spin traps, have been proposed as a mechanism.

Delta-9-tetrahydrocannabinol protects cardiac cells from hypoxia via CB2 receptor activation and nitric oxide production.

Delta-9-tetrahydrocannabinol (THC), the major active component of marijuana, has a beneficial effect on the cardiovascular system during stress conditions, but the defence mechanism is still unclear. The present study was designed to investigate the central (CB1) and the peripheral (CB2) cannabinoid receptor expression in neonatal cardiomyoctes and possible function in the cardioprotection of THC from hypoxia. Pre-treatment of cardiomyocytes that were grown in vitro with 0.

Flavins are source of visible-light-induced free radical formation in cells.

Background And Objectives: It has been hypothesized that reactive oxygen species (ROS) are created by an endogenous photosensitizer during low energy visible light illumination of tissue, and these ROS are responsible for reported biostimulative effects. This study aims to identify the endogenous photosensitizer responsible for ROS production by visible light.

Study Design/materials And Methods: Electron paramagnetic resonance (EPR) spectroscopy was used to detect oxyradicals produced in cardiac and sperm cells during illumination by a halogen lamp.

Low-energy laser irradiation promotes cellular redox activity.

Low-energy visible light (LEVL) has been shown to stimulate cell functions. This is called "photobiostimulation" and has been used successfully over the last three decades for treating a range of conditions, including soft tissue injuries, severe wounds, chronic pain, and more. Nevertheless, the mechanism of photobiostimulative processes is still being debated.

Low energy visible light induces reactive oxygen species generation and stimulates an increase of intracellular calcium concentration in cardiac cells.

Low energy visible light (LEVL) irradiation has been shown to exert some beneficial effects on various cell cultures. For example, it increases the fertilizing capability of sperm cells, promotes cell proliferation, induces sprouting of neurons, and more. To learn about the mechanism of photobiostimulation, we studied the relationship between increased intracellular calcium ([Ca2+]i) and reactive oxygen species production following LEVL illumination of cardiomyocytes.