Stadler Istvan, Lanzafame Raymond J, Oskoui Philip, Zhang Ren-Yu, Coleman John, Whittaker Megan
The Laser Center, Rochester General Hospital, Rochester, New York 14621-3095, USA.
Photomed Laser Surg. 2004 Jun;22(3):227-31. doi: 10.1089/1549541041438560.
This study investigated the change in local skin temperature in black and white mice during irradiation at 830 nm.
The photostimulation effect low-level laser therapy (LLLT) (700-900 nm) is widely accepted and used. However, the exact biological mechanisms of biostimulation are not yet established.
Groups of C57BL/6J and BALB/cJ mice (n = 12 in each group) were lightly anesthetized with 50% carbon dioxide and 50% oxygen. The dorsum was shaved and a 1.0 x 0.5 cm spot was marked in the same location on each subject. Animals were photo-irradiated with a diode laser (CW, 830 nm, 36 mW output at 5 cm distance). Fluences of 0.0-5.0 J/cm(2) were delivered. Skin surface temperature was monitored by a thermal camera. Two thermocouples were placed 1 mm below the skin surface at the site of light exposure.
Temperature increased with increasing fluences of exposure. The surface temperature change at 5.0 J/cm(2) was 6.25 x 10(-2) +/- 2.0 x 10(-3) vs. 1.2 x 10(-2) +/- 3.0 x 10(-3) degrees C/mW for black and white mice, respectively. The temperature change at 1.0 mm depth was 4.51 x 10(-2) +/- 3.0 x 10(-3) vs. 0.83 x 10(-2) +/- 1.0 x 10(-3), respectively.
CW irradiation at 830 nm and 5.0 J/cm(2) fluence induces a small temperature increase at the surface and at 1 mm in depth. The smaller effects seen in white mice might be due in part to reflection. This suggests that the thermal effects of irradiation at 830 nm are unlikely to explain the LLLT effect. However skin color should be considered, particularly at higher fluences. Further investigations are warranted to correlate the melanin content of the skin with observed LLLT effects.
本研究调查了830nm照射期间黑白小鼠局部皮肤温度的变化。
低强度激光疗法（LLLT）（700 - 900nm）的光刺激效应已被广泛接受和应用。然而，生物刺激的确切生物学机制尚未确立。
将C57BL/6J和BALB/cJ小鼠分组（每组n = 12），用50%二氧化碳和50%氧气轻度麻醉。剃去背部毛发，在每只动物的同一位置标记一个1.0×0.5cm的区域。用二极管激光器（连续波，830nm，5cm距离处输出功率36mW）对动物进行光照射。给予的能量密度为0.0 - 5.0J/cm²。用热成像仪监测皮肤表面温度。在光照部位皮肤表面下方1mm处放置两个热电偶。
温度随照射能量密度的增加而升高。在5.0J/cm²时，黑色和白色小鼠的表面温度变化分别为6.25×10⁻²±2.0×10⁻³和1.2×10⁻²±3.0×10⁻³℃/mW。在1.0mm深度处的温度变化分别为4.51×10⁻²±3.0×10⁻³和0.83×10⁻²±1.0×10⁻³。
830nm连续波照射和5.0J/cm²的能量密度在皮肤表面和1mm深度处引起了小幅度的温度升高。白色小鼠中观察到的较小效应可能部分归因于反射。这表明830nm照射的热效应不太可能解释低强度激光疗法的效果。然而，应考虑皮肤颜色，尤其是在较高能量密度时。有必要进一步研究将皮肤黑色素含量与观察到的低强度激光疗法效果相关联。
