Cell attachment to extracellular matrices is modulated by pulsed radiationat 820 nm and chemicals that modify the activity of enzymes in the plasma membrane

Background and Objective: Adhesive interactions between cells and extracell ular matrices play a regulative role in wound repair processes. The objecti ve of this investigation is to study action mechanisms of pulsed radiation at 820 nm on cellular adhesion in vitro. Light emitting diodes (LED) at 820 nm are widely used for treatment of wounds of various etiology. Study Design/Materials and Methods: The LED (820 +/- 10 nm, 10 Hz, 16-120 J /m(2)) is used for the irradiation of HeLa cell suspension. In parallel exp eriments, amiloride (5 x 10(-4) M), ouabain (7 x 10(-5) M, 7 x 10(-4) M), q uinacrine (6 x 10(-4) M), arachidonic acid (1 x 10(-5) M), glucose (2 x 10( -4) M), and ATP (5 x 10(-5) M) are added to the cell suspension before or a fter the irradiation procedure. The cell-glass adhesion is studied using th e adhesion assay technique described in Lasers Surg Med 1996; 18:171. Results: Cell-glass adhesion increases in a dose-dependent manner following the irradiation. Preirradiation eliminates the inhibition of cell attachme nt caused by ouabain, arachidonic acid, and ATP. The inhibitive effect of q uinacrine on the cell attachment is eliminated by the irradiation performed after the treatment with the chemical. Irradiation and amiloride have a sy nergetic stimulative effect on the cell attachment. The threshold dose for the cell attachment stimulation by the irradiation is decreased by the trea tment of the cell suspension with amiloride or ouabain. Conclusion: The results obtained indicate that pulsed IR radiation at 820 n m increases the cell-matrix attachment. It is the modulation of the monoval ent ion fluxes through the plasma membrane and not the release of arachidon ic acid that is involved in the cellular signaling pathways activated by ir radiation at 820 nm. Preirradiation has a protective effect against the inh ibitive action of ouabain, arachidonic acid, ATP, and quinacrine on cell at tachment process. It is supposed that irradiation activates those signaling pathways in cells which attenuate the inhibitive action of these chemicals . (C) 2001 Wiley-Liss, Inc.