부산대학교 도서관

Exposures of the skin with electromagnetic radiation of wavelengths between 670 nm and 1400 nm are often used as a general treatment to improve wound healing and reduce pain, for example, in chronic diabetic skin lesions. We investigated the effects of water-filtered infrared A ( wIRA) and of narrow-band IR-A provided by a light-emitting diode LED ( LED- IR-A) irradiation in vitro on 3T3 fibroblast cultures under defined conditions with and without glyoxal administration. Glyoxal triggers the formation of advanced glycation end products, thereby mimicking a diabetic metabolic state. Cell viability and apoptotic changes were determined by flow cytometry after vital staining with Annexin V, YO- PRO-1 and propidium iodide ( PI), and by SubG1 assay. Mitochondrial function and oxidative stress were examined by vital staining for radical production, mitochondrial membrane potential ( MMP) and the ratio of reduced-to-oxidized glutathione ( GSH/ GSSG). The metabolic state was monitored by a resazurin conversion assay. The numbers of apoptotic cells were reduced in cultures irradiated with wIRA or LED- IR-A. More mitochondria showed a well-polarized MMP after wIRA irradiation in glyoxal damaged cells. LED- IR-A treatment specifically restored the GSH/ GSSG ratio. The immediate positive effects of wIRA and LED- IR-A observed in living cells, particularly on mitochondria, reflect the therapeutic benefits of wIRA and LED- IR-A. [ABSTRACT FROM AUTHOR]