| Autor: |
Quirk B; Department of Neurology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA., Whelan HT; Department of Neurology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA. |
| Jazyk: |
angličtina |
| Zdroj: |
Photobiomodulation, photomedicine, and laser surgery [Photobiomodul Photomed Laser Surg] 2021 Jul; Vol. 39 (7), pp. 463-470. Date of Electronic Publication: 2021 Jun 10. |
| DOI: |
10.1089/photob.2020.4978 |
| Abstrakt: |
Objective: To study the effects of 670 and 830 nm irradiation on oxygen consumption by cytochrome c oxidase (CCO) in a Clark electrode type reaction chamber. To explore the effect of irradiation on the nitric oxide (NO) donor-induced inhibition of oxygen consumption. Background: Most theories of photobiomodulation (PBM) involve the enzyme CCO as a cellular target for red-to-near infrared light (R-NIR) irradiation. Attempts to measure the effect of irradiation on the kinetics of CCO have failed to demonstrate a significant effect. It remains to explore the effects of irradiation on the consumption of oxygen. NO has been proposed as a possible mediator for PBM due to its inhibitory effects on CCO. Studying the effect of R-NIR on NO-induced inhibition of oxygen consumption is needed to explore this thesis. Methods: Oxygen consumption assays at 22°C were performed in a Mitocell MT200A system equipped with a 1302 oxygen electrode. R-NIR irradiation at 670 nm (41 mW/cm 2 ) or 830 nm (31 mW/cm 2 ) was provided to the reaction mixture. Calculated second-order rate constants were compared with control runs at four cytochrome c concentrations. Assays were also performed with or without NO donor and/or light for two substrate concentrations. Results: Kinetics constants for oxygen consumption with or without R-NIR showed no significant differences with either wavelength at any substrate concentration. The NO donor showed significant inhibition that was not relieved by irradiation. Conclusions: This lack of effect by R-NIR calls into question both the CCO activity model and the NO inhibition relief model of PBM. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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