title: Low-intensity near-infrared laser radiation-induced changes of acetylcholinesterase activity of human erythrocytes.
abstract: OBJECTIVE
  The aim of the present study was to investigate the transformations of red blood cells produced by low-intensity infrared laser radiation (810 nm).
  
  
  BACKGROUND
  Low-intensity (the output power of a laser device in the milliwatt range) laser radiation as a local phototherapeutic modality is characterized by its ability to induce non-thermic, nondestructive photobiological processes in cells and tissues. However, the exact theory concerning the therapeutic effects of laser biostimulation has not been developed.
  
  
  METHODS
  The suspensions of human erythrocytes in PBS (10% hematocrit) were irradiated with near-infrared (810 nm) therapy laser at different light doses (0-20 J) and light power (fluence rate; 200 or 400 mW) at 37 degrees C. As the parameters characterizing the cell structural and functional changes membrane acetylcholinesterase (AchEase) activity, the membrane potential, the level of intracellular glutathione, the level of products of membrane lipid peroxidation, and the cell osmotic stability were measured.
  
  
  RESULTS
  It was found that near-infrared low-intensity laser radiation produced complex biphasic dose-dependent changes of the parameters of AchEase reaction in the dose-dependent manner: at smaller doses of radiation (6 J) the maximal reaction rate and Michaelis-Menten constant value decreased, and at higher radiation doses these parameters increased. No significant changes of erythrocyte stability, cellular redox state (reduced glutathione or lipid peroxidation product levels), or cell membrane electrochemical potential were observed.
  
  
  CONCLUSIONS
  Low-intensity near-infrared laser radiation (810 mn) produced AchEase activity changes, reflecting the effect of light on the enzyme due to energy absorption. Protein molecule conformational transitions and enzyme activity modifications in cells have been suggested as laser radiation-induced events.
authors.affiliation: Department of Rehabilitation, Medical University of Lodz, Lodz, Poland. jkujawa@box43.gnet.pl
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kujawa
authors.forename: Leu
authors.initials: L
authors.lastname: Zavodnik
authors.forename: Ilya
authors.initials: I
authors.lastname: Zavodnik
authors.forename: Maria
authors.initials: M
authors.lastname: Bryszewska
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D004307:Dose-Response Relationship, Radiation; D004910:Erythrocyte Membrane / Q000201:enzymology / Q000528:radiation effects; D004912:Erythrocytes / Q000201:enzymology* / Q000528:radiation effects*; D006801:Humans; D028022:Low-Level Light Therapy; D008564:Membrane Potentials / Q000528:radiation effects; D008968:Molecular Conformation / Q000528:radiation effects
chemical_list: D000110:Acetylcholinesterase