Effects of He-Ne laser irradiation on chromatin properties and synthesis of nucleic acids in human peripheral blood lymphocytes.
Irradiation of human peripheral blood lymphocytes with an He-Ne laser (at 632.8 nm) at doses between 28 and 112 J m-2 caused changes in the chromatin during the first 6 h after exposure that were similar to those found after stimulation of the lymphocytes by phytohaemagglutinin (PHA), i.e. it increased chromatin accessibility to the low-molecular-mass ligand acridine orange (AO) and increased incorporation of the labelled RNA precursor [14C]uridine into the cells. The curves of AO-chromatin binding and RNA synthesis after either He-Ne irradiation with an He-Ne laser (56 J m-2) or PHA treatment were multipeak in nature. For the first 6 h after stimulation the curves for the two treatments were similar. After 7 h, the rate of RNA synthesis in laser-irradiated lymphocytes dropped to the control level, whereas in the PHA-stimulated cells [14C]uridine incorporation increased substantially. Unlike the case with PHA, treatment with an He-Ne laser did not induce resumption of DNA synthesis in lymphocytes. Lymphocytes irradiated by laser in the presence of interleukin-2 (IL-2) retained the level of labelled-thymidine incorporation characteristic of intact cells cultivated in the presence of IL-2. On the other hand, irradiation by an He-Ne laser produced a potentiating action on the response of peripheral blood lymphocytes to PHA, with thymidine incorporation being stimulated. This effect may explain the mechanism of wound healing by an He-Ne laser radiation: chromatin activation in the cells of wounds and ulcers makes these cells more responsive to the natural stimulators present in tissues.
Smol'yaninova
N K
NK
Laser Technology Centre, Academy of Sciences of the USSR, Moscow.
Karu
T I
TI
Fedoseeva
G E
GE
Zelenin
A V
AV
D002843:Chromatin / Q000187:drug effects / Q000528:radiation effects*; D004261:DNA Replication / Q000528:radiation effects*; D006371:Helium; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology; D007700:Kinetics; D007834:Lasers; D008213:Lymphocyte Activation / Q000528:radiation effects*; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000528:radiation effects*; D008297:Male; D009356:Neon; D012313:RNA / Q000096:biosynthesis* / Q000528:radiation effects; D013698:Templates, Genetic; D013997:Time Factors; D014529:Uridine / Q000378:metabolism
D002843:Chromatin; D007376:Interleukin-2; D006371:Helium; D009356:Neon; D012313:RNA; D014529:Uridine