Currently the methods of laser and non-laser (incoherent monochromic, narrow-band or broadband) light blood irradiation therapy - the methods of photohemotherapy - are widely applied in the treatment of different pathologies. Direct intravenous and extracorporeal (with red, UV and blue light) as well as transcutaneous (with red and infrared light) irradiation of blood are used. Unlike the treatment mechanisms of procedures of local laser therapy, the medical effects of photohemotherapy methods are determined by predominance of systemic healing mechanisms above the local ones, increasing the efficacy of functioning of vascular, respiratory, immune, other systems and organism as a whole.

The method of HeNe intravenous laser blood irradiation (LBI) was developed in experiment and introduced in clinic in 1981 by soviet scientists E.N. Meshalkin and V.S. Sergievskiy. Originally the method was applied in the treatment of cardiovascular pathologies. Some authors reported that the treatment possibilities of the method are very large and include the improvement of rheological characteristics of the blood and microcirculation, normalization of parameters of hormonal, immune, reproductive and many other systems.

HeNe laser (632.8 nm) is generally used for carrying out the intravenous laser blood irradiation (IV LBI). Usual parameters of blood irradiation procedure are: output power at the end of the light-guide inserted into a vein from 1 up to 3mW, exposition 20 - 60 minutes. Procedures are conducted on a daily base, from 3 up to 10 sessions on a course of therapy.

It was shown, that IV HeNe LBI stimulates the immune response of the organism, activates erythrogenesis and improves deformability of erythrocyte membranes, has anti-hypoxic activity on tissues and general antitoxic influence on the organism at different pathological processes. IV LBI is used for its biostimulative, analgetic, antiallergic, immunocorrective, antitoxic, vasodilative, antiarrhythmic, antibacterial, antihypoxic, spasmolytic, anti-inflammatory and some other properties.

IV LBI activates nonspecific mechanisms of anti-infectious immunity. Intensifying of bactericidal activity of serum of the blood and system of the complement, reduction of the degree of C - reactive protein, level of average molecules and toxicity of plasma, increasing the content of IgA, IgM and IgG in the serum of the blood, as well as decreasing of the level of circulating immune complexes are proved. There are studies on boosting effect of IV LBI on the cellular part of immunity (N. F. Gamaleya et al., 1991). Under influence of IV LBI the phagocytic activity of macrophages markedly increases, concentration of microbes in exudate in the abdominal cavity of patients with peritonitis decreases, reduction of inflammatory exhibiting of disease, activation of microcirculation are detected.

The medical effect of IV LBI is stipulated by its immuno-corrective activity by normalization of intercellular relationships within the subpopulation of T-lymphocytes and increasing the amount of immune cells in a blood. It elevates the function activity of B-lymphocytes, strengthens the immune response, reduces the degree of intoxication and as a result improves the general condition of patients (V. S. Sergievskiy at al., 1991).

IV LBI promotes improving the rheological properties of blood, rising fluidity and activating transport functions. That is accompanied by increasing the oxygen level, as well as decreasing the carbon dioxide partial pressure. The arterio-venous difference by oxygen is enlarged, that testifies the liquidation of a tissue hypoxia and enrichment the oxygenation. It is a sign of normalization of tissue metabolism. Probably, the basis of activation of oxygen transport function of IV LBI is the influence on hemoglobin with transforming it in more favorable conformation state. The augmentation of oxygen level improves metabolism of the organism tissues. In addition, the laser irradiation activates the ATP synthesis and energy formation in cells (A. S. Krjuk et al., 1986). Application of IV LBI in a cardiology has shown that procedures have analgetic effect, show reliable rising tolerance of patients towards physical tolerance test, elongation of the period of remission.

It was proved that IV LBI reduces aggregation ability of thrombocytes, activates fibrinolysis, which results in peripheral blood flow velocity increasing and tissues oxygenation enriching. The improvement of microcirculation and utilization of oxygen in tissues as a result of IV LBI is intimately linked with positive influence on metabolism: higher level of oxidation of energy-carrying molecules of glucose, pyruvate, and other substances.

The improvement in microcirculation system is also stipulated by vasodilation and change in rheological properties of blood as a result of drop of its viscosity, decrease of aggregation activity of erythrocytes due to changes of their physicochemical properties, in particular rising of negative electric charge. Finally the activation of microcirculation, unblocking of capillaries and collaterals, improvement of tissue trophical activity, normalization of a nervous excitability are take place (N. N. Kapshidze et al., 1993).

IV LBI is recommended to apply before surgical operations as preparation for intervention, as well as in the postoperative stage, because the laser irradiation of blood has not only analgetic effect, but also spasmolytic and sedative activity.

IV LBI procedures on patients with chronic glomerulonephritis allow overcoming resistance towards medicament therapy (glucocorticoid, cytostatic, hypotensive and diuretic drugs).

IV LBI promotes rising of concentration of antibiotics in the focus of inflammation as a result of improvement the microcirculation in the focus of inflammation, as well as normalization the morphology and functional activity of the affected organ as a whole.

IV LBI procedures have found broad application in obstetrics and gynecology for activation the blood flow in utero-placental and feto-placental basins, for prophylaxis the pathology at delivery, for influence on inflammatory processes of inner genital organs. IV LBI normalizes production of gonadotropins, improves microcirculation, elevates oxygen pressure in blood and in tissues, and so accelerates the process of regeneration and reparation.

In order to explain the generalized and multifactor effects of IV LBI, its positive influence practically on all tissues and functional systems of the body, clinical effectiveness for the treatment of different diseases, some authors mentioned that the improvement of microcirculation after IV LBI is detected in all structures of central nervous system, but this improvement the most active in the hypothalamus, which has highly developed vascular system. The capillaries of a hypothalamus are remarkable for high permeability for macro-molecular proteins, which should even more amplify influence of the irradiated blood to subthalamic nuclei. So it is supposed, that IV LBI increases the functional activity of hypothalamus and all limbic system, and as a result the activation of energetic, metabolism, immune and vegetative responses, mobilization of adaptive reserves of an organism is reached.

The application in clinics of the non-invasive and relatively simple method of infrared (IR) transcutaneous laser irradiation of blood becomes possible after development of suitable IR semiconductor laser diodes.

For transcutaneous LBI lasers with red (630-670 nm) or near IR (800-1300 nm) irradiation band are applied. Laser light is delivered to the skin on a projection of large veins or arteries via special nozzles.

Some recent studies suggested that it is possible to achieve the medical effect similar to effect of IV HeNe LBI, without intravenous manipulations - by transcutaneous laser blood irradiation (TLBI).

The procedure of TLBI have the greatest application in children's practice. The method grounded on a relatively high permeability of the skin and hypodermic tissues for radiation of red and especially of IR spectrum. It is supposed, that the efficacy of 20 mW HeNe laser transcutaneous blood irradiation is equal to 1 mW HeNe laser intravenous blood irradiation. In the same time TLBI procedures are non-invasive and painless. Recently non-laser light sources are also applied for transcutaneous blood irradiation.

Unfortunately, there are not enough qualified works on comparing medical and biological effects of IV and transcutaneous LBI to make the final suggestions about clinical equality of these methods. At the same Е. Brill (1994) suggested that the effects of the laser therapy depend on the method of irradiation. He considered, that the term «transcutaneous laser blood irradiation» is disorient the explorer, as skips the significance in definition of bioeffect of irritation of receptors of the skin and acupuncture points, dermal cells (including mast cells), adventitious elements of the vascular wall and other formations which are subject to the irradiation. For today there are no bases to consider, that the positive therapeutic effect of laser irradiation of skin - is a result of influence only of that part of energy, which penetrates the skin and is absorbed by blood and its components. With the good reasons it is possible to speak about transcutaneous laser irradiation, with indication of the place of delivery of laser light.