The stimulatory effect of low energy light (LEL) has been attributed to irradiation-induced ROS formation. In the present study we demonstrate that irradiating various cell cultures such as fibroblasts, cardiac and sperm cells with UVA or various light sources in the visible range results in singlet oxygen and OH radical formation. These radicals were monitored by using the EPR technique. We believe that the light induced ROS could mediate previously documented effects of LEL on these cells.

Confocal microscopy was used for irradiation and observation of the same area of interest, allowing the imaging of low power laser effects in subcellular components and functions, at the single cell level. Coverslips cultures of human fetal foreskin fibroblasts (HFFF2) were placed in a small incubation chamber for in vivo microscopic observation. Cells were stimulated by the 647 nm line of the Argon- Krypton laser of the confocal microscope (0.1 mW/cm²). Membrane permeability, mitochondrial membrane potential ((delta) Psi_m), intracellular pH_i, calcium alterations and nuclear chromatin accessibility were monitored, at different times after irradiation, using specific fluorescent vital probes. Images were stored to the computer and quantitative evaluation was performed using image- processing software. After irradiation, influx and efflux of the appropriate dyes monitored changes in cell membrane permeability. Laser irradiation caused alkalizatoin of the cytosolic pH_i and increase of the mitochondrial membrane potential ((delta) Psi_m). Temporary global Ca²⁺ responses were also observed. No such effects were noted in microscopic fields other than the irradiated ones. No toxic effects were observed, during time course of the experiment.

Exposure of cultured skin cells to low power visible light leads to a transiently stimulated proliferation. Facilitation of this response requires the presence of active PKC, elevation of intracellular calcium, and involves reactive oxygen species. In the present study, the role of PKC(alpha) and PCK(eta) was examined using paired murine fibroblasts, differing in the level of these isozymes expression. The ability of the cells to respond to low power UVA light or HeNe laser by stimulated proliferation was correlated with an active state or overexpression of PKC(alpha) , but not PKC(eta) . A parallel response was obtained in cells that were loaded with A1PcS₄ before photosensitization. Whenever this latter treatment caused a light-stimulated inhibition, it was accompanied by the intracellular calcium and photosensitizer dynamics typical of the effect of PDT on rate epithelial cells. Accordingly, added antioxidants that suppressed light-stimulated proliferation also suppressed this light-stimulated inhibition. The model systems employed in this study are the first to demonstrate the specific effect of PKC isozymes on light-stimulated proliferation, in relation to oxidative stress, and indicate their dual role in light-tissue interaction.

The low power laser radiation is widely applied for treatment of various diseases. In our research we investigated the influence of low power laser radiation on the mast cells degranulation process. The object of the research were the mesentery mast cells of the rat thin intestine. A loop of thin intestine was irradiated by the therapeutic diode laser device Uley - 2K (lambda - 890 nm, pulse). The process of mast cells degranulation served as a criterion for their functional activity estimation. The estimation was fulfilled with the help of light microscope (toluidine blue staining, pH02,0; degranulating mast cells counting on 100 cells; immersion technique; X 980). To study the dependence of degranulation process of mast cells irradiated with lasre from intracellular calcium (Ca²⁺) concentration we applied 0,000015 M solution of verapamil, which was applied to the mesentery for 2 minutes. Laser radiation (890 nm) stimulates mesentery mast cells degranulation. This effect is dose-dependent. Maximal degranulation was registered after laser irradiation wiht power 25 mW, exposure time 15-30 s (energy density 7.5 x 10³ J/m² to 6 x 10⁴ j/m²). Further increasing of exposure time caused the effect decreasing. The results of our experiments with verpamil let us suppose light interaction with the voltage-dependent subunit of calcium channel, changing intracellular Ca²⁺ and leading to stimulatory effects.

A possibility of control of lipid peroxidation level in myocardium tissues by using of low-power laser light and luminescent radiation during reperfusion period of isolated heart after ischemia was observed. The effect is connected to reactivation of antioxidant enzymes by red light.

Sandwich 25micrometers -thick cells with transparent electrodes, filled with some fatty acids (FA) important for the biological membrane (BM), and their mixtures with cholesterol, in the liquid crystal (LC) state, were subjected to a flow of thermal neutrons (4.15 x 10¹² neutrons/cm²). Microstructural aspects, electric behaviour and nonlinear optical effects under lower power laser beams were studied before and after irradiation. The laser interaction with FA in the LC state shows the influence of the thermal neutrons irradiation on the electric conduction and the molecular arrangements in the LC systems. Before irradiation, a lens-like effect u nder a He-Ne laser beam has been noticed in the unsaturated (UFA) acids; due to the self-phase modulation effect, a ring pattern appear in far field. The presence of cholesterol (ch) in mixtures modified these effects. After irradiation, the optical nonlinear effects change their feature, increasing in UFA and occurring also in some saturated acids (SFA). These changes are in agreement with the microscopical aspects, the color modifications, and with the electrical state change. The mixture samples are analyzed too. A month after irradiation, SFA seem to slowing return to the initial state, but UFA samples do not come back to the state before irradiation. The nonlinear optical behavior changes dramatically. Ch slightly modifies these changes.

The paper investigated in vivo the influence of low-intensity laser radiation (he-Ne laser with wavelength 0,63 nm) on the mean velocity of their movement. It is known that characteristic of cardiovascular diseases (CVD) are microcirculation disturbances and disorder in rheological properties of blood. Therefore these investigations were carried out on cardiac ischemia patients. The blood perfusion valve and the mean velocity were measured by the method of photon correlation spectroscopy with the use of fiber optic cables. As the radiation source, a semiconductor laser with wavelength 780 nm (0,8 mW) was used. It has been found that, between the erythrocytes and the mean velocity of their movement there is an inverse dependence on the time of irradiation of patients.

Problem demyelinating diseases from actual in modern of neurology. Main disease of this group - multiple sclerosis, which morphological manifestation is the process demyelineation - disintegration of myelin, which covers axial cylinders of nervous filaments. The outcome of such damage is violation of realization of nervous impulses, dissonance of implement and coordination functions. Most typical the feature of a multiple sclerosis is origin of repeated remissions, which compact with indication remyelination. In development of disease the large role is played by modifications of immunological of a reactivity of an organism. The purpose of the title is development of new methods of treatment of a multiple sclerosis because of lasertherapy. For thsi purpose the influence of a laser exposure on demyelination and remyelination processes will be investigated, is investigated pathological fabrics at microscopic and submicroscopic levels. The study of proceses demyelination and remyelination will be conducted on experimental animals (rats), which are sick experimental allergic encephalomyelitis (EAE), that is the most adequate model of a multiple sclerosis. The patients' EAE animals will be subjected to treatment by a laser exposure. For want of it there will be determinate optimum lengths of waves, dozes and modes of laser radiation.

In recent years the treatment of blood with low intensity laser irradiation has become popular in a variety of clinical applications due to its anti-inflammatory, biostimulative and immune-stimulatory effects etc. Despite of wide using of laser blood irradiation in the pediatric practice there is lack of information concerning the sensitivity of children blood cells to laser irradiation. At present study the influence of the He-Ne laser irradiation on the lipid physico-chemical state in lymphocytes and isolated erythrocyte membranes of 8-16 years old children using lipophilic fluorescence probe pyrene was investigated in vitro. It was shown that fluorescence parameters of pyrene incorporated into erythrocyte and lymphocyte membranes after laser irradiation ((lambda) equals 630nm) at dose of 24 J/cm² at t equals 18 +/- 2 (degree)C were unchanged. The intensity of intrinsic protein UV-fluorescence ((lambda)_ex equals 297 nm, (lambda)_em equals 332 nm) of lymphocytes exposed to the same irradiation was decreased insignificantly. The obtained data indicate that He-Ne laser irradiation at the above dose does not affect the lipid microviscosity of erythrocyte and lymphocyte membranes.

To study the effect of He-Ne irradiation (632.8 nm, 15 mW/cm²) on spontaneous contractive activity the fragments of rat portal vein weremounted isometrically in Krebs buffer. Irradiation of vessel fragments by He-Ne laser during 3,5 and 10 min caused the decrease of ton up to 50%, which lasted in postirradiation period (the observation time - 10 min). The frequency of phasic and tonic contractions did not change, but the amplitude increased up to 40% as compared to the initial level. The decreased basal tone level and the increased amplitude of phasic oscillations lasted in postirradiation period. Adding NO synthasa blocator (N - nitro-L-arginine) to Krebs solution before irradiation caused no significant changes mentioned above parameters. Irradiation and coputing of the same parameters of spontaneous contractive activity of vena porta caused no effects, mentioned in the absence of the blocator. From the results it is concluded that the decrease of tone is evoked by the increase of EDRF production and cGMP. The increase of amplitude of phasic and tonic contractions is connected with increase of Ca⁺⁺ entry in every contraction cycle as a result of membrane Ca⁺⁺ pool increase.

We report on experimental proves of light-induced changes in the transmission spectrum of human venous blood under the action of low- intensity radiation from He-Ne laser. The transmission spectra of diluted and nondiluted heparinized human blood have been analyzed before, after and in the course of irradiation. The reproducible variations of the blood transmission spectrum in the range 730-780 nm have been observed. These changes have been shown to correlate with oxygen saturation. The decreased oxygen saturation in venous blood is stabilized at the level of about 70-80% from the initial one after 5-8 procedures of laser irradiation.