Actual Isothermal Effects of Water‐Filtered Infrared A‐Irradiation. (12th March 2015)

• Record Type: Journal Article
• Authors: Höhn, Annika; Hartmann, Petra; Gebhart, Veronika; Sonntag, Johanna; Grune, Tilman; Jung, Tobias
• Is Part Of: Photochemistry and photobiology. Volume 91:Number 4(2015:Jul./Aug.)
• Page Start: 887
• Page End: 894
• Publication Date: 2015-03-12
• Subjects: Photochemistry -- Periodicals; Light -- Physiological effect -- Periodicals; 541.35
• DOI: 10.1111/php.12439
• Languages: English
• ISSNs: 0031-8655

Abstract

<abstract abstract-type="main" id="php12439-abs-0001"> <title>Abstract</title> <p>In this study, the athermal effects of water‐filtered infrared A (wIRA)‐irradiation (780–1400 nm) on human dermal fibroblasts were investigated. For this purpose, cells were exposed to wIRA‐irradiation (178 mW cm<sup>−2</sup> for 1 h), while a sophisticated experimental setup prevented warming of the samples exceeding 0.1°C. The investigated parameters were the formation of reactive oxygen species (ROS), mitochondrial membrane potential and superoxide release, protein oxidation, proliferation rate, as well as intracellular Ca<sup>2+</sup>‐release in single cells, most of them quantified via fluorescence microscopy and fluorimetric techniques. The existence of actual athermal wIRA‐effects is still intensively discussed, since their detection requires a careful experimental setup and both efficient and powerful temperature regulation of the exposed samples. Here, we can definitively show that some of the supposed athermal wIRA‐effects may be rather artifacts, since wIRA did not reveal any impact on the above mentioned parameters—as long as the temperature of the exposed cells was carefully maintained. Though, we were able to identify an athermal DNA‐protective wIRA‐effect, since the induced DNA damage (quantified via 8‐Oxo‐G‐formation) was significantly decreased after a subsequent UVB‐exposure. These results suggest that many of the supposed athermal wIRA‐effects can be induced by pure warming of the samples, independent from any wIRA‐irradiation.</p> </abstract>