Dose-dependent effect of cadaverine on hydroxyl radicals’ production by human peripheral blood leukocytes

Objective. To assess changes in the generation of hydroxyl radicals by leukocytes under the influence of cadaverine at concentrations of 1, 5 and 25 mmol/L. Materials and methods. Peripheral venous blood samples were obtained from 40 apparently healthy donors. To assess the production of hydroxyl radicals, a luminol-dependent chemiluminescence reaction with blood leukocytes, which were pre-incubated with cadaverine at concentrations of 1, 5 and 25 mmol/L was carried out. The study was conducted on a Luminoskan Ascent® Thermo Labsystems (USA) luminometer for 180 minutes. For statistical analysis, the integral chemiluminescence indicator for the entire measurement period (RLU) was used. The time to reach the maximum of light flashes in minutes, the intensity of the utmost glow, and the area under the luminescence extinction curve were calculated. Results. It was determined that pre-incubation of cells with cadaverine significantly reduces their time to reach the maximum generation of hydroxyl radicals. In addition, cadaverine enhances the intensity of the reaction of luminol-dependent chemiluminescence of leukocytes of healthy donors, and the greatest stimulating effect was recorded at a polyamine concentration of 5 mmol/L (p =0,009 to samples with a spontaneous reaction, p =0,007 and 0,010 to samples with cadaverine 1 mmol/L and 5 mmol/L respectively). Cadaverine increases the area under the reaction curve, it being the most significant at a concentration of 5 mmol/L – 20.89±3.00 c.u. versus 0.86±0.07 c.u. with a spontaneous reaction (p=0,001). Conclusions. The results of the study indicate a possible effect of cadaverine on the mechanisms of hydroxyl radical formation, as well as the activity of the diamine oxidase enzyme in leukocytes. It can be supposed that the combination of these effects contributes to the development of the environment favorable for microorganisms at the focus of inflammation. Thus, microorganisms that produce cadaverine, which modulates the generation of hydroxyl radicals by leukocytes, adapt to their environment, creating a special type of microenvironment, which probably results in an asymptomatic course of the inflammatory process.