<title>Changes of rheologic properties of blood in experimental animals irradiated with low-energy lasers</title>

Abstract

The effect of infrared laser radiation on viscosity of serum and blood in experimental animals was investigated. The experiment was carried out on 30 male guinea pigs weighing 280 - 320 g. Fifteen animals composed a group irradiated with laser, the other 15 animals made up a control group in which no irradiation was made. A semiconductive laser generating infrared radiation (wavelength -- 904 nm, frequency -- 800 Hz, pulse duration -- 200 ns, mean power - - 8.7 mW) was used. The right infracostal region of the animal was irradiated 3 minutes daily for 15 consecutive days. After the end of the experiment in the obtained blood and serum the measurement of hematocrit and rheologic examination was made in the temperature of 310 K. The estimation of viscosity of whole blood was made by means of low-gradient viscosimeter `low shear,' for shearing velocities: D1 equals 0.116 s-1 and D2 equals 4.59 s-1. The viscosity of serum was estimated using Ubbelohd's microviscosimeter. A significant increase of whole blood viscosity measured for shearing velocity D1 was obtained in irradiated animals as compared to the controls. No statistically significant differences in viscosity of whole blood at clotting speed D2, viscosity of serum and hematocrit were observed between both groups of animals. The obtained data prove a distinct effect of low-energy laser radiation on rheologic properties of blood in experimental animals. The increase of whole blood viscosity, observed only at low shearing velocities, is probably related to the changes of structural and functional properties of cell membranes of erythrocytes resulting in a decrease of aggregation.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.