ROLE OF ΚB AND AP-1 TRANSCRIPTION FACTORS IN CHANGES IN NITRIC OXIDE PRODUCTION AND UTILIZATION IN THE HEART OF RATS UNDER CHRONIC FLUORIDE INTOXICATION

Fluorides, being hazardous contaminants of soil and drinking water, can get in excessive amounts into human and animal bodies. This is especially true for regions where the fluoride content in soils is very high, for example, Poltava, Dnipropetrovsk, and Kirovohrad regions in Ukraine. Excessive fluoride intake can change the rate of nitric oxide production. The impact of fluorides on changes in nitric oxide production and metabolism in the heart and the role of redox-sensitive transcription factors in these changes are poorly understood. The aim of this study was to determine the effect of activation of κB transcription factors and activator protein 1 on the activity of inducible NO-synthase, constitutive isoforms of NO-synthase, nitrite and nitrate reductase, arginase, concentration of nitrites, peroxynitrite and nitrosothiols in the heart of rats during chronic fluoride intoxication. Materials and methods. The study was performed on 24 adult male Wistar rats weighing 220-260 grams. Animals were randomly divided into 4 groups of 6 animals in each (control, chronic fluoride intoxication group, κB blockade group and activator protein 1 blockade group). The experiment lasted 30 days. We determined the activity of inducible NO-synthase, constitutive isoforms of NO-synthase, the concentration of peroxynitrite alkali and alkaline earth metals, the concentration of nitrites and nitrosothiols, the activity of nitrite reductase, nitrate reductase and arginase. Results. Chronic fluoride intoxication increases the activity of inducible NO-synthase by 1.74 times, does not affect the activity of constitutive isoforms and reduces the activity of arginase by 35.68% compared with the control group of animals. The concentration of nitrites in the heart of rats increases 1.73 times, peroxynitrite 1.43 times, and the concentration of nitrosothiols doubled. The use of κB transcription factor blockers and activator protein 1 reduces nitric oxide production from NO synthases and reduces the concentrations of all nitric oxide metabolites in the heart of rats under conditions of chronic fluoride intoxication. Conclusions. Activation of κB transcription factors and activator protein 1 during chronic excessive intake of fluoride leads to hyperproduction of nitric oxide in the heart of rats due to increased activity of inducible NO-synthase and nitrite reductases. Excess production of nitric oxide under chronic fluoride intoxication leads to the accumulation of nitrites, peroxynitrite and nitrosothiols in the heart of rats.

CHANGES IN THE ACTIVITY OF INDUCIBLE NO-SYNTHASE AND ARGINASE, THEIR RELATIONSHIP WITH THE LEVEL OF PRO- AND ANTI-INFLAMMATORY CYTOKINES IN CERVICAL MUCUS IN PREGNANT WOMEN, WHO UNDERWENT IVF AND ARE AT RISK OF PRETERM CHILDBIRTH

Introduction. Nitric oxide (NO) produces a wide range of bioregulatory effects. Imbalance in the ratio of the activity of inducible NO-synthase and arginase in favor of iNOS can lead to a pro-inflammatory reaction. At the risk of preterm childbirth, the content of proinflammatory cytokines increases both at the local and systemic levels. The aim of this work is to study the relationship between changes in the content of pro- and anti-inflammatory cytokines and the activity of inducible NO-synthase and arginase in the cervical mucus of women with in vitro fertilization (IVF), who are at risk of preterm childbirth. Materials and methods. The test group (TG) included 37 women, who underwent IVF and presented prognostic signs, indicating a high risk of preterm birth in the future. The control group (CP) consisted of 20 healthy pregnant women, who did not undergo assisted reproductive technologies. We determined the indicators of inducible NO-synthase activity and total arginase activity, as well as the level of pro- and anti-inflammatory cytokines in the mucus of the cervical canal of the participants at their 28-34 weeks of pregnancy. Results and discussion. The activity of iNOS in TG significantly increased (in 2.57 times) compared to healthy pregnant women (CP), while the activity of arginase, on the contrary, decreased significantly (in 1.91 times). There was a significant increase in the levels of pro-inflammatory cytokines INF-γ and TNF-α in the TG women, while they demonstrated the significantly reduced concentration of anti-inflammatory cytokine IL-10. In cervical mucus taken from TG women, positive correlations were found between an increase in the concentration of the proinflammatory cytokine INF-γ and an increase in iNOS activity, between a decrease in IL-10 levels and arginase activity, and a negative relationship between an increase in iNOS activity and a decrease in arginase activity. Conclusions. The detected cytokine imbalance in pregnant women, who underwent in vitro fertilization and were at risk of preterm childbirth, together with a impaired ratio of iNOS and arginase, indicates an inappropriate level of immunosuppression. These immune changes, by activating cellular responses of maternal immunity, can contribute to preterme childbirth.

The effect of photobiomodulation therapy of some indices of rats’ blood cells functional state under experimental diabetes mellitus

Background. Diabetes mellitus is a chronic endocrine-metabolic disease caused by an absolute or relative insulin deficiency. During diabetes, there are perfect conditions for the development of oxidative stress: the content of substrates for oxidation increases, the content of natural antioxidants decreases and the activity of antioxidant systems is suppressed. It is known that photobiomodulation therapy produce antioxidant and antihyperglycemic effects. Here we investigated its influence on blood system functioning. Materials and Methods. The study was performed on male Wistar rats. Experimental diabetes mellitus was induced by the intraperitoneal injection of streptozotocin. Leukocyte formula was calculated using blood smears stained by Romanowsky–Giemsa. Catalase activity was determined spectrophotometrically. Affinity of hemoglobin to oxygen was evaluated by spectrophotometric method in Ivanov’s modification by drawing oxygenation curves. The protoporphyrin content in whole blood was measured by analyzing its fluorescence spectra. The content of NO2-, total and inducible NO synthase activity was determined spectrophotometrically. Results. Under the action of photobiomodulation therapy on healthy animals, there was a shift of oxygenation curves to the left and a decrease of P50, whereas under irradiation of rats with diabetes, there was a shift of oxygenation curves to the right and increase in P50 compared to indices in nonirradiated animals. During diabetes, there was a decrease in protoporphyrin content compared to control, but there was a tendency to increase under photobiomodulation. Photobiomodulation therapy of rats with diabetes increased catalase activity in erythrocyte hemolysates. We revealed significant changes in leukocyte formula under photobiomodulation. The total NO synthase activity in leukocytes of rats with diabetes was higher compared to healthy animals, but decreased under the action of photobiomodulation. We found an increase in inducible NO synthase activity in leukocytes of rats with diabetes and in leukocytes of irradiated healthy animals. An increase in NO2- content in leukocytes of rats with diabetes was detected. Under photobiomodulation, NO2- content was significantly lower in rats with diabetes. Conclusion. Photobiomodulation therapy produces a corrective action on blood system during diabetes, in particular, it improves oxygen release from hemoglobin and prevents hypoxia. Simultaneously with the increase in tissue oxygen saturation, a decrease in NO synthase activity and nitrite content along with an increase in catalase activity prevents the development of oxidative stress.

Sevoflurane Promotes Bactericidal Properties of Macrophages through Enhanced Inducible Nitric Oxide Synthase Expression in Male Mice

Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Sevoflurane with its antiinflammatory properties has shown to decrease mortality in animal models of sepsis. However, the underlying mechanism of its beneficial effect in this inflammatory scenario remains poorly understood. Macrophages play an important role in the early stage of sepsis as they are tasked with eliminating invading microbes and also attracting other immune cells by the release of proinflammatory cytokines such as interleukin-1β, interleukin-6, and tumor necrosis factor-α. Thus, the authors hypothesized that sevoflurane mitigates the proinflammatory response of macrophages, while maintaining their bactericidal properties. Methods Murine bone marrow–derived macrophages were stimulated in vitro with lipopolysaccharide in the presence and absence of 2% sevoflurane. Expression of cytokines and inducible NO synthase as well as uptake of fluorescently labeled Escherichia coli (E. coli) were measured. The in vivo endotoxemia model consisted of an intraperitoneal lipopolysaccharide injection after anesthesia with either ketamine and xylazine or 4% sevoflurane. Male mice (n = 6 per group) were observed for a total of 20 h. During the last 30 min fluorescently labeled E. coli were intraperitoneally injected. Peritoneal cells were extracted by peritoneal lavage and inducible NO synthase expression as well as E. coli uptake by peritoneal macrophages was determined using flow cytometry. Results In vitro, sevoflurane enhanced lipopolysaccharide-induced inducible NO synthase expression after 8 h by 466% and increased macrophage uptake of fluorescently labeled E. coli by 70% compared with vehicle-treated controls. Inhibiting inducible NO synthase expression pharmacologically abolished this increase in bacteria uptake. In vivo, inducible NO synthase expression was increased by 669% and phagocytosis of E. coli by 49% compared with the control group. Conclusions Sevoflurane enhances phagocytosis of bacteria by lipopolysaccharide-challenged macrophages in vitro and in vivo via an inducible NO synthase–dependent mechanism. Thus, sevoflurane potentiates bactericidal and antiinflammatory host-defense mechanisms in endotoxemia.