Ankri Rinat, Friedman Harry, Savion Naphtali, Kotev-Emeth Shlomo, Breitbart Haim, Lubart Rachel
Department of Physics, Bar Ilan University, Ramat Gan 52900, Israel.
Lasers Surg Med. 2010 Apr;42(4):348-52. doi: 10.1002/lsm.20849.
Visible light-based stimulation using low-intensity lasers, LEDs, and broadband visible light devices has been recently introduced for therapy of human tissues in the absence of exogenous photosensitizers. Nitric oxide (NO) formation might be a potential mechanism for photobiomodulation because it is synthesized in cells by nitric oxide synthase (NOS), which contains both flavin and heme groups that absorb visible light. NO synthesis may also result from increased reactive oxygen species (ROS), which are found in various cell cultures following visible light illumination. NO is mainly known for inducing blood vessel dilation by endothelial cells, and in sperm cells NO is considered as an important agent in acrosome reaction and capacitation process, which are essential for successful fertilization.
To study NO formation in endothelial and sperm cells following visible light irradiation.
Sperm and endothelial cells were illuminated with broadband visible light, 400-800 nm, 130 mW/cm(2), for 5 minutes. During illumination, the endothelial cells were incubated in PBS free of Ca(+2) and Mg(+2), and the sperm cells were incubated in NKM buffer, to induce "stress conditions." NO production was quantified by using the Griess reagent which reacts with nitrite in the medium to yield an Azo compound which has an absorption band at 540 nm.
Visible light illumination increased NO concentration both in sperm and endothelial cells. Blue light was more effective than red. Light-induced NO occurred only when endothelial cells were incubated in PBS free of Ca(+2) and Mg(+2), and in sperm cells, only when incubated in NKM.
Light induces NO formation in endothelial and sperm cells. In endothelial cells, NO formation may explain previous results demonstrating enhanced wound healing and pain relief following illumination. In illuminated sperm cells, NO formation may account for the enhanced fertilization rate.
最近，在没有外源性光敏剂的情况下，已开始使用低强度激光、发光二极管和宽带可见光设备进行基于可见光的人体组织刺激治疗。一氧化氮（NO）的形成可能是光生物调节的潜在机制，因为它是由一氧化氮合酶（NOS）在细胞中合成的，该酶同时含有能吸收可见光的黄素和血红素基团。可见光照射后，各种细胞培养物中发现的活性氧（ROS）增加也可能导致NO合成。NO主要以诱导内皮细胞血管扩张而闻名，在精子细胞中，NO被认为是顶体反应和获能过程中的重要介质，而这两个过程对于成功受精至关重要。
研究可见光照射后内皮细胞和精子细胞中NO的形成。
用400 - 800 nm、130 mW/cm²的宽带可见光照射精子和内皮细胞5分钟。照射期间，内皮细胞在不含Ca²⁺和Mg²⁺的磷酸盐缓冲液（PBS）中孵育，精子细胞在NKM缓冲液中孵育，以诱导“应激条件”。使用格里斯试剂对NO生成进行定量，该试剂与培养基中的亚硝酸盐反应生成在540 nm处有吸收带的偶氮化合物。
可见光照射增加了精子和内皮细胞中的NO浓度。蓝光比红光更有效。光诱导的NO仅在内皮细胞于不含Ca²⁺和Mg²⁺的PBS中孵育时产生，而在精子细胞中，仅在NKM中孵育时产生。
光诱导内皮细胞和精子细胞中NO的形成。在内皮细胞中，NO的形成可能解释了先前关于照射后伤口愈合增强和疼痛缓解的结果。在受照射的精子细胞中，NO的形成可能是受精率提高的原因。
