[Dynamic analysis of modification of peripheral neutrophils functional activity and its regulation during tumor growth in vivo].

Polymorphonuclear granulocytes (neutrophils) release the reactive oxygen species (ROS) for destruction of pathogens, providing quicker of an organism from infections and own defective of transformed cells. Reactive oxygen species are also potential carcinogens because they facilitate mutagenesis, tumor promotion and progression. Balance between these opposite influences is supported by coordinated interrelations in intracellular signaling systems. Tumor growth influence on the NADPH oxidase in peripheral innate immune cells is unclear. A solid cancer model was developed after an intramuscular injection of Ehrlich carcinoma cells into hind leg of NMRI strain mice. Intensity of the respiratory burst was estimated by luminol-dependent chemiluminescence technique. Transformation of inflammatory reaction was revealed during tumor growth: greater amounts of neutrophils were recruited into peritoneal cavity; sizes of the cells, their nuclei and granules were enlarged; the ratio of different cell types in peritoneal exudation was changed. The study revealed that tumor progression was accompanied by significant changes in functional activity of neutrophils. Dynamic increase in spontaneous level of ROS production and concentration-dependent change of intensity of the respiratory burst induced with chemotactic peptide N-formyl-Met-Leu-Phe (fMLF) was revealed in peripheral neutrophils under tumor growth conditions. It was found that effects of inhibitors of tyrosine protein kinases, protein kinase C, mitogen-activated protein kinase p38MAPK (p38MAPK) and phosphatidylinositol 3-kinase (PI3K) were altered in neutrophils from tumor-bearing mice in comparison with the cells of control mice. This indicates a change in the role of the enzymes in regulation of the neutrophil respiratory burst. Data obtained show that p38MAPK and PI3K entangle up- and down-regulation of NADPH oxidase in peripheral neutrophils during tumor growth.

Immunomodulating action of low intensity millimeter waves on primed neutrophils.

Comparative investigation of the susceptibility of intact and primed neutrophils of the NMRI strain mice to low intensity millimeter wave (mm wave) irradiation (41.95 GHz) was performed. The specific absorption rate was 0.45 W/kg. Isolated neutrophils were primed by a chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) at a subthreshold concentration of 10 nM for 20 min, and then the cells were activated by 1 microM fMLP. Production of the reactive oxygen species (ROS) was estimated by the luminol dependent chemiluminescence technique. It was found that the preliminary mm wave irradiation of the resting cells at 20 degrees C did not act on the ROS production induced by the chemotactic peptide. The exposure of the primed cells results in a subsequent increase in the fMLP response. Therefore, the primed neutrophils are susceptible to the mm waves. Specific inhibitors of the protein kinases abolished the mm wave effect on the primed cells. The data indicate that protein kinases actively participate in transduction of the mm wave signal to effector molecules involved in neutrophil respiratory burst.

[Alkaline DNAse from rat brain]. / Shchelochnaia DNKaza golovnogo mozga krys.

A DNAse was isolated from rat brain and purified 1100-fold using affinity chromatography on a column with DNA-agarose and chromatography on granulated hydroxyapatite. The electrophoretically pure Mg2+, Mn2+-dependent enzyme preparation hydrolyzes the denaturated DNA with a maximal activity at pH 8,4. The optimal terminal concentration of Mg2+ corresponds to the Mg/phosphorus molar ratio of the substrate is 1:2. For Mn2+ this correlation is 1:1. Using the immobilized substrate method, the exonuclease type of DNAse activity has been established. The enzyme activity depends on the state of its SH-groups; the reaction is inhibited by pCMB. The molecular weight of DNAase as determined by gel-filtration through Sephadex G-200 is equal to 60 000.