University of California San Diego, Department of Neuroscience, 9500 Gilman Drive MTF316, La Jolla, CA 92093-0624, USA.
Brain Res. 2010 Jan 8;1306:100-5. doi: 10.1016/j.brainres.2009.10.022. Epub 2009 Oct 23.
Transcranial near infrared laser therapy (NILT) improves behavioral outcome following embolic strokes in embolized rabbits and clinical rating scores in acute ischemic stroke (AIS) patients; however, the cellular mechanism(s) involved in NILT neuroprotection have not been elucidated. It has been proposed that mitochondrial energy production may underlie a response to NILT, but this has not been demonstrated using an in vivo embolic stroke model. Thus, we evaluated the effect of NILT on cortical ATP content using the rabbit small clot embolic stroke model (RSCEM), the model originally used to demonstrate NILT efficacy and initiate the NEST-1 clinical trial. Five minutes following embolization, rabbits were exposed to 2 min of NILT using an 808 nm laser source, which was driven to output either continuous wave (CW), or pulsed wave modes (PW). Three hours after embolization, the cerebral cortex was excised and processed for the measurement of ATP content using a standard luciferin-luciferase assay. NILT-treated rabbits were directly compared to sham-treated embolized rabbits and naïve control rabbits. Embolization decreased cortical ATP content in ischemic cortex by 45% compared to naive rabbits, a decrease that was attenuated by CW NILT which resulted in a 41% increase in cortical ATP content compared to the sham embolized group (p>0.05). The absolute increase in ATP content was 22.5% compared to naive rabbits. Following PW NILT, which delivered 5 (PW1) and 35 (PW2) times more energy than CW, we measured a 157% (PW1 p=0.0032) and 221% (PW2 p=0.0001) increase in cortical ATP content, respectively, compared to the sham embolized group. That represented a 41% and 77% increase in ATP content compared to naive control rabbits. This is the first demonstration that embolization can decrease ATP content in rabbit cortex and that NILT significantly increases cortical ATP content in embolized rabbits, an effect that is correlated with cortical fluence and the mode of NILT delivery. The data provide new insight into the molecular mechanisms associated with clinical improvement following NILT.
经颅近红外激光治疗（NILT）可改善栓塞性兔缺血性中风模型的行为学预后和急性缺血性中风（AIS）患者的临床评分；然而，NILT 神经保护作用的细胞机制尚未阐明。有人提出，线粒体能量产生可能是对 NILT 反应的基础，但这尚未通过体内栓塞性中风模型得到证明。因此，我们使用兔小栓子栓塞性中风模型（RSCEM）评估了 NILT 对皮质 ATP 含量的影响，该模型最初用于证明 NILT 的疗效并启动 NEST-1 临床试验。栓塞后 5 分钟，用 808nm 激光源对兔进行 2 分钟的 NILT 照射，激光源以连续波（CW）或脉冲波模式（PW）驱动。栓塞后 3 小时，取出大脑皮质，用标准荧光素-荧光素酶测定法测定 ATP 含量。将 NILT 治疗的兔与假手术栓塞的兔和正常对照的兔直接进行比较。与正常对照的兔相比，栓塞使缺血皮质中的皮质 ATP 含量降低了 45%，而 CW NILT 可减轻这种降低，使皮质 ATP 含量比假手术栓塞组增加 41%（p＞0.05）。与正常对照的兔相比，ATP 含量的绝对增加为 22.5%。在 PW1（PW1）和 PW2（PW2）分别输送 CW 5 倍和 35 倍能量的 PW NILT 后，我们分别测量到皮质 ATP 含量增加了 157%（PW1，p=0.0032）和 221%（PW2，p=0.0001），与假手术栓塞组相比。与正常对照的兔相比，ATP 含量分别增加了 41%和 77%。这是首次证明栓塞可以降低兔皮质中的 ATP 含量，并且 NILT 可显著增加栓塞兔的皮质 ATP 含量，这种作用与皮质通量和 NILT 输送模式相关。该数据为与 NILT 后临床改善相关的分子机制提供了新的见解。
