ABSTRACT
BACKGROUND AND OBJECTIVES: Adhesive interactions between cells and extracellular matrices play a regulative role in wound repair processes. The objective 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 experiments, amiloride (5 x 10(-4) M), ouabain (7 x 10(-5) M, 7 x 10(-4) M), quinacrine (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 after the irradiation procedure. The cell-glass adhesion is studied using the 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 attachment caused by ouabain, arachidonic acid, and ATP. The inhibitive effect of quinacrine on the cell attachment is eliminated by the irradiation performed after the treatment with the chemical. Irradiation and amiloride have a synergetic stimulative effect on the cell attachment. The threshold dose for the cell attachment stimulation by the irradiation is decreased by the treatment of the cell suspension with amiloride or ouabain. CONCLUSIONS: The results obtained indicate that pulsed IR radiation at 820 nm increases the cell-matrix attachment. It is the modulation of the monovalent ion fluxes through the plasma membrane and not the release of arachidonic acid that is involved in the cellular signaling pathways activated by irradiation at 820 nm. Preirradiation has a protective effect against the inhibitive action of ouabain, arachidonic acid, ATP, and quinacrine on cell attachment process. It is supposed that irradiation activates those signaling pathways in cells which attenuate the inhibitive action of these chemicals.
Subject(s)
Cell Membrane/metabolism , Cell Membrane/radiation effects , Enzyme Activators/metabolism , Enzyme Activators/radiation effects , Extracellular Matrix/metabolism , Extracellular Matrix/radiation effects , Adenosine Triphosphate/metabolism , Adenosine Triphosphate/radiation effects , Amiloride/metabolism , Amiloride/radiation effects , Analysis of Variance , Arachidonic Acid/metabolism , Arachidonic Acid/radiation effects , Cell Adhesion/physiology , Cell Adhesion/radiation effects , Cell Membrane/enzymology , Dimethyl Sulfoxide/metabolism , Dimethyl Sulfoxide/radiation effects , Extracellular Matrix/enzymology , Glucose/metabolism , Glucose/radiation effects , HeLa Cells , Humans , In Vitro Techniques , Ouabain/metabolism , Ouabain/radiation effects , Quinacrine/metabolism , Quinacrine/radiation effectsABSTRACT
Active sodium transport was completely and irreversibly inhibited in toad urinary bladders photolyzed in the presence of iodoamiloride.
Subject(s)
Amiloride/radiation effects , Pyrazines/radiation effects , Sodium/metabolism , Urinary Bladder/drug effects , Amiloride/analogs & derivatives , Amiloride/pharmacology , Animals , Anura , Biological Transport, Active/drug effects , In Vitro Techniques , Ultraviolet Rays , Urinary Bladder/metabolismABSTRACT
A photosensitive binding reaction is described in which an analog of amiloride is bound to sites that control sodium entry into frog skin. This reaction results in irreversible inhibition of net sodium transport.
