BACKGROUND AND OBJECTIVE: The purpose of this study was to evaluate the possible role of reactive oxygen species (ROS) in mediating previously recorded alterations in DNA synthesis, inducible by low-intensity laser irradiation (LILI), in the haemopoietic cell line U937. STUDY DESIGN/ MATERIALS AND METHODS: The ability of LILI (660 nm, 12 mW, 5 kHz) to induce ROS from U937 cells was assessed spectrophotometrically at energy densities (E.D.) from 1.0 to 11.5 J/cm2. In order to assess whether laser-induced ROS could alter cellular proliferation DNA synthesis was measured post-irradiation, by the incorporation of tritiated thymidine (3H-TdR) into the cells in both the presence and absence of the antioxidant catalase (CAT). RESULTS: Detectable ROS were produced post-irradiation only from the differentiated form of the cell line. Analysis by Student's t-test for unrelated groups showed a significant difference, at E.D.s 2.9 and 8.6 J/cm2, in the extent of DNA synthesis occurring in cells irradiated in the presence of CAT or in its absence. CONCLUSION: These findings demonstrate that laser-inducible ROS can mediate laser's effects on this cell line.
BACKGROUND AND OBJECTIVE: The purpose of this study was to evaluate the possible role of reactive oxygen species (ROS) in mediating previously recorded alterations in DNA synthesis, inducible by low-intensity laser irradiation (LILI), in the haemopoietic cell line U937. STUDY DESIGN/ MATERIALS AND METHODS: The ability of LILI (660 nm, 12 mW, 5 kHz) to induce ROS from U937 cells was assessed spectrophotometrically at energy densities (E.D.) from 1.0 to 11.5 J/cm2. In order to assess whether laser-induced ROS could alter cellular proliferation DNA synthesis was measured post-irradiation, by the incorporation of tritiated thymidine (3H-TdR) into the cells in both the presence and absence of the antioxidant catalase (CAT). RESULTS: Detectable ROS were produced post-irradiation only from the differentiated form of the cell line. Analysis by Student's t-test for unrelated groups showed a significant difference, at E.D.s 2.9 and 8.6 J/cm2, in the extent of DNA synthesis occurring in cells irradiated in the presence of CAT or in its absence. CONCLUSION: These findings demonstrate that laser-inducible ROS can mediate laser's effects on this cell line.
Authors: Gregory M Dittami; Suhrud M Rajguru; Richard A Lasher; Robert W Hitchcock; Richard D Rabbitt Journal: J Physiol Date: 2011-01-17 Impact factor: 5.182
Authors: Ying-Ying Huang; Kazuya Nagata; Clark E Tedford; Thomas McCarthy; Michael R Hamblin Journal: J Biophotonics Date: 2012-12-27 Impact factor: 3.207
Authors: Aaron C-H Chen; Praveen R Arany; Ying-Ying Huang; Elizabeth M Tomkinson; Sulbha K Sharma; Gitika B Kharkwal; Taimur Saleem; David Mooney; Fiona E Yull; Timothy S Blackwell; Michael R Hamblin Journal: PLoS One Date: 2011-07-21 Impact factor: 3.240