Donors of NO and pulsed radiation at =820 nm exert effects on cell attachment to extracellular matrices

The adhesion of HeLa cells to a glass matrix was evaluated after the irradiation of the cell suspension with a pulsed near-infrared light-emitting diode ( =820 nm, frequency 10 Hz, dose 8–120 J/m) and treatment with two donors of nitric oxide, sodium nitroprusside (SNP, 5×10 M) and NaNO2 (4×10 −4 M). It was found that in an irradiated cell suspension, the cell–glass adhesion increases in a dose-dependent manner (a bell-shaped curve with a maximum at 60 J/m). The treatment of cells with SNP or NaNO2 before the irradiation eliminates the radiation-induced attachment stimulation. Pretreatment of cells with SNP not only eliminates the radiation-induced attachment stimulation but inhibits the attachment of irradiated (but not non-irradiated) cells. It is suggested that a modulation of the activity of respiratory chain (probably the alteration of the activity of cytochrome c oxidase) is involved in radiation-induced increase of cell attachment. © 2001 Elsevier Science Ireland Ltd. All rights reserved.