Southbohemian University in České Budějovice, Faculty of Health and Social Studies, Department of Radiology and Toxicology, Czech Republic.
J Photochem Photobiol B. 2012 Dec 5;117:111-4. doi: 10.1016/j.jphotobiol.2012.08.009. Epub 2012 Sep 7.
Several authors have suggested that low level laser light may have a positive influence on side effects caused by ionizing radiation therapy. We therefore studied indicators of oxidative stress after exposure to gamma radiation with or without pre-exposure to low level laser light. Groups of mice were exposed to light from a laser diode at a wavelength of 830 nm, delivering an energy of 20 or 100 J to 1cm(2) in the abdominal part of the animal with a power density of 300 mW/cm(2) in continuous regime. Following this treatment (or sham irradiation), mice were irradiated with graded doses of (60)Co gamma rays. Levels of superoxide dismutase and malondialdehyde were measured in murine blood cells 30 min or 3 days after exposure. For both time points, there was a clear increase of superoxide dismutase and malondialdehyde with gamma dose, but laser light (alone or in combination with gamma irradiation) did not seem to have any influence on either parameter. Because the physical parameters in our experiments were similar to those of studies showing a positive effect of laser pre-exposure, we conclude that the lack of an observed effect in our case was due to differences in biological parameters, i.e. to differences between the tissues or cell types studied. It is also possible, of course, that laser effects would be seen mainly in the skin immediately exposed, and not to the same degree in blood cells circulating through that area, which were exposed to considerably smaller laser energies.
一些作者提出，低水平激光可能对电离辐射治疗引起的副作用产生积极影响。因此，我们研究了在γ射线照射前或照射后暴露于低水平激光下氧化应激的指标。将小鼠分为几组，用波长为 830nm 的激光二极管照射，在动物腹部以 300mW/cm²的连续功率密度照射 1cm²，能量为 20 或 100J。照射后（或假照射），用（60）Coγ射线对小鼠进行分级照射。在照射后 30 分钟或 3 天，测量小鼠血液中的超氧化物歧化酶和丙二醛水平。对于这两个时间点，超氧化物歧化酶和丙二醛的水平都随着γ剂量的增加而明显增加，但激光（单独或与γ辐射联合使用）似乎对这两个参数都没有影响。由于我们实验中的物理参数与显示激光预处理积极效果的研究相似，我们得出结论，在我们的情况下，没有观察到效果是由于生物学参数的差异，即研究的组织或细胞类型的差异。当然，也有可能激光的影响主要出现在立即暴露的皮肤中，而在通过该区域循环的血细胞中则不会出现相同程度的影响，这些血细胞暴露于较小的激光能量下。
