Magdalena Mackiewicz-Milewska, Jan Talar, Grzegorz Grześk, Leszek Szadujkis-Szadurski, Irena Bułatowicz, Zbigniew Śliwiński

Magdalena Mackiewicz-Milewska, Jan Talar, Grzegorz Grześk, Leszek Szadujkis-Szadurski, Irena Bułatowicz, Zbigniew Śliwiński – The role of nitric oxide in the modulation of arterial smooth muscle contraction evoked by activation of adrenoreceptors during laser biostimulation. Fizjoterapia Polska 2002; 2(2); 89-98

Abstract
Introduction. The mechanisms of action of laser biostimulation on tissue continues to be the object of scientific investigation. The positive impact of laser radiation of low and medium power on inhibiting vascular contraction has been proven. It remains unknown, however, exactly how this takes place. We investigated the role of nitric oxide in this process.Material and methods. An in vitro experiment was performed on isolated tail arteries of male Wistar rats. The arteries were first subjected to the effect of noradrenalin (NA) and phenylephrine (PHE), and then to the effect of laser radiation (10, 30 and 100 mW), Then an inhibitor of nitric oxide synthase was added to the incubation fluid, along with methylene blue, and the effects of laser radiation in these conditions were observed.Results. Laser radiation of 10, 30, and 110mW inhibits the vascular contraction reaction induced by NA and PHE. The addition of a nitric oxide inhibitor or a guanyl cyclase inhibitor (methylene blue) to the incubation fluid cancels the inhibitory effect of laser biostimulation on contraction. Conclusion. Our results imply that the inhibitory effect of laser biostimulation on vascular contraction is mediated by nitric oxide and its secondary transmitter, guanyl cyclase.

Key words:
laser biostimulation, vascular endothelium, Nitric Oxide, adrenoreceptors