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

The adhesion of HeLa cells to a glass matrix was evaluated after the irradi ation of the cell suspension with a pulsed near-infrared light-emitting dio de (lambda = 820 nm, frequency 10 Hz, dose 8-120 J/m(2)) and treatment with two donors of nitric oxide, sodium nitroprusside (SNP, 5 x 10(-4) M) and N aNO2 (4 x 10(-4) M). It was found that in an irradiated cell suspension, th e cell-glass adhesion increases in a dose-dependent manner (a bell-shaped c urve with a maximum at 60 J/m(2)). The treatment of cells with SNP or NaNO2 before the irradiation eliminates the radiation-induced attachment stimula tion. Pretreatment of cells with SNP not only eliminates the radiation-indu ced attachment stimulation but inhibits the attachment of irradiated (but n ot non-irradiated) cells. It is suggested that a modulation of the activity of respiratory chain (probably the alteration of the activity of cytochrom e c oxidase) is involved in radiation-induced increase of cell attachment. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.