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Visible light induces no formation in sperm and endothelial cells
Author(s) -
Ankri Rinat,
Friedman Harry,
Savion Naphtali,
KotevEmeth Shlomo,
Breitbart Haim,
Lubart Rachel
Publication year - 2010
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.20849
Subject(s) - sperm , microbiology and biotechnology , chemistry , andrology , biology , medicine
Background 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. Purpose To study NO formation in endothelial and sperm cells following visible light irradiation. Materials and Methods 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. Results 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. Conclusion 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. Lasers Surg. Med. © 2009 Wiley‐Liss, Inc.