Cardio- and Vasoprotective Effects of Quinacrine in an In Vivo Rat Model of Myocardial Ischemia/Reperfusion Injury.

This study aimed to investigate the cardioprotective effect of quinacrine in an in vivo model of myocardial ischemia/reperfusion injury. A 30-min regional myocardial ischemia followed by a 2-h reperfusion was modeled in anesthetized Wistar rats. Starting at the last minute of ischemia and during the first 9 min of reperfusion the rats in the control (n=8) and experimental (n=9) groups were injected with 0.9% NaCl and quinacrine solution (5 mg/kg), respectively. The area at risk and infarct size were evaluated by "double staining" with Evans blue and triphenyltetrazolium chloride. To assess vascular permeability in the area at risk zone, indocyanine green (ICG) and thioflavin S (ThS) were injected intravenously at the 90th and 120th minutes of reperfusion, respectively, to assess the no-reflow zone. The images of ICG and ThS fluorescence in transverse sections of rat hearts were obtained using a FLUM multispectral fluorescence organoscope. HR tended to decrease by 13% after intravenous administration of quinacrine and then recovered within 50 min. Quinacrine reduced the size of the necrotic zone (p=0.01), vascular permeability in the necrosis region, and the no-reflow area (p=0.027); at the same time, the area at risk did not significantly differ between the groups. Intravenous administration of quinacrine at the beginning of reperfusion of the rat myocardium reduces no-reflow phenomenon and infarct size.

Effect of Azithromycin on Myocardial Resistance to Ischemia/Reperfusion in Systemic Inflammatory Response Syndrome and Alimentary Obesity.

The study focuses on the effects of azithromycin on severity of ischemia/reperfusion myocardial injury during simulated systemic inflammatory response syndrome (SIRS) in primary visceral obesity (PVO). Total ischemia/reperfusion was modeled by Langendorff perfusion of isolated heart with following estimation of the size of myocardial infarction. SIRS was accompanied by an increase in blood levels of proinflammatory cytokines and LPS. Combination of PVO and SIRS produced no significant changes in the infarct size compared to the control. Administration of azithromycin to rats with PVO and SIRS resulted in pronounced alterations of biochemical and immunological parameters, although it did not affect the infarct size. In contrast, the use of tetracycline increased the size of myocardial infarction. This phenomenon should be taken into consideration in antimicrobial therapy.

Effect of Combined Antimicrobial Therapy on Ischemia/Reperfusion Myocardial Injury in Rats with Acute Inflammation of the Large Intestine against the Background of Alimentary Obesity.

We studied the effect of combined antimicrobial therapy with amoxicillin, metronidazole, and clarithromycin on the severity of ischemia/reperfusion myocardial injury in Wistar rats with alimentary obesity and acute inflammation of the large intestine. General ischemia/reperfusion was reproduced on Langendorff-perfused isolated hearts and infarct size was estimated. Acute inflammation of the large intestine was accompanied by an increase in the blood levels of proinflammatory cytokines. The presence of obesity and acute inflammation of the large intestine did not significantly affect the infarct size in comparison with the control. Administration of antimicrobial drugs to animals with obesity and acute inflammation of the large intestine led to a significant increase in the infarct size, which should be considered when prescribing antimicrobial therapy to patients with comorbidity.

[INFLUENCE OF PROBIOTIC STRAIN E. FAECIUM L3 ON MYOCARDIAL TOLERANCE TO ISCHEMIA-REPERFUSION INJURY IN THE MODEL OF ANTIBIOTIC-INDUCED INTESTINAL DYSBIOSIS].

Functional parameters and degree of myocardial damage by ischemia-reperfusion model of isolated heart were investigated during acute experiments on rats with an antibiotic-induced intestinal dysbiosis after administration of the probiotic strains of Enterococcus faecium L3. Administration of antimicrobial drugs has resulted in an increased heart rate and in an increase in coronary flow of isolated heart. Administration of enterococci after the global ischemia has caused rats to have a decrease in diastolic pressure, increased systolic and pulse pressure, and an increased intensity of coronary flow. The article presents data on changes in the composition of the intestinal microbiota and the immune system that was previously obtained in studies based on this experimental model.

[CARDIOPROTFETIVE EFECTS OF NECROSTATIN-7 IN THE RAT MODEL OF PERMANENT CORONARY OCCLUSION].

The cardioprotective effects of necroptosis inhibitor necrostatin-7 were studied in the rat model of permanent coronary occlusion. It was found that intraperitoneal injection of necrostatin-7 at a dose of 14.5 mg/kg 60 minutes prior to permanent left coronary artery occlusion reduced the amount of scar tissue and scar length in the left ventricle on the 21st day after surgery. In addition, pretreatment with necrostatin-7 resulted in decreased plasma level of N-terminal pro-brain natriuretic peptide, which points to the improvement in left ventricular function.

[Correcting influence of music on the students' functional state].

The influence of listening to classical music on integral indices of the activity of the regulatory mechanisms of the heart rhythm in students after teaching load was tested with the method of variational pulsometry accordingly to R.M Baevsky procedure. Registration and analysis of ECG was realized on Pentium 4 in three experimental situations: before the start of lessons (norm), after lessons, after listening to the music. Two types of response of students 'functional state to the teaching load: sympathetic and parasympathetic have been established. After teaching load music therapy session was found to led to the shift of levels of all examined indices of heart rhythm toward the original data (norm), most expressed in students with a sympathetic response type.

Study of cardioprotective effects of necroptosis inhibitors on isolated rat heart subjected to global ischemia-reperfusion.

The cardioprotective effects of necroptosis inhibitors necrostatin-1 and necrostatin-5 were studied on the isolated heart model in rats. Intraperitoneal injection of necrostatin-1 (1.65 mg/kg) or necrostatin-5 (2.46 mg/kg) 60 min before reperfusion of the isolated heart reduced the infarction zone caused by 30-min global ischemia and 120-min reperfusion. Intracoronary injection of necrostatin-1 (44.5 µmol/liter) caused an increase of left-ventricular systolic pressure, that is produced a positive inotropic effect, but did not reduce the infarction zone.

[Antitoxic influence of taurine].

The investigation of single injection of taurine on Lebetina viper' venom-induced shifts of morpho-functional indices of rats' peripheral blood was carried out. It was revealed that taurine eliminates negative effects of influence of venom. The results of investigation allow us to assume that taurine trigger adaptive and compensatory mechanisms of organism in conditions of toxins influence.

Cardioprotective properties of dimethyl sulfoxide during global ischemia-reperfusion of isolated rat heart.

Cardioprotective properties of dimethyl sulfoxide (DMSO) were studied in the isolated rat heart model. Intraperitoneal administration of DMSO to animals for 3 days before the experiment, but not addition of DMSO to the perfusate, reduced infarction size. Both intraperitoneal and intracoronary administration of DMSO reduced the severity of postischemic left-ventricular dysfunction.

Passive and active target delivery of drugs to ischemic myocardium.

Silica nanoparticles as carriers for targeted drug delivery to the heart were studied. Studies of hemodynamic parameters of rats after intravenous infusion of silica nanoparticles showed no acute toxicity. Intravenous infusion of silica nanoparticles to animals with ischemia-reperfusion of the myocardium led to accumulation of the nanoparticles in the focus of injury, which attests to possibility of passive targeted drug delivery to the myocardium.

[Myocardial protection against global ischemia-reperfusion with use of Krebs-Henseleit buffer-based cardioplegic solution].

Improvement of myocardial protection against global ischemia-reperfusion injury during cardiopulmonary bypass remains to be of primary importance for cardiac surgery. In the present study, the effectiveness of new Krebs-Henseleit buffer-based cardioplegic solution was investigated in an isolated rat heart preparation in normo- and hypothermic states. Use of this crystalloid cardioplegic solution in the normothermic mode (37 degrees C) resulted in better myocardial protection in comparison to standard cardioplegic solutions as evidenced from both infarct size data and the patterns of left ventricular postischemic recovery. The data obtained indicate that Krebs-Henseleit buffer-based cardioplegic solution might be recommended for further preclinical testing.

[Morphofunctional parameters as criteria for assessing the students' adaptation to graded physical exercise].

Short-term physical exercise (Roufie test) was studied for its impact on the physiometric and functional parameters of first-year students engaged in a basic physical training group. According to the reaction to exercise and gender, the authors formed 3 groups: (1) girls with excellent performance after Roufie-Dixon; (2) girls and boys with good performance; (3) girls and boys with satisfactory performance. The changes in the study parameters indicated that the Roufie exercise test was adequate for Group I girls and Group 2 boys, in whom the adaptive potential after exercise was in the range of adaptive changes. In the other groups, short-term physical exercise led to adaptive potential transition toward the tension area. The changes of other study parameters were adequate to those in the adaptive potential during an exercise test.

[Effects of medicinal plant species on gymnasium pupils' cardiac performance under exam stress].

The use of antistress tea from the medicinal herb species "Treasure of Nature" as a dietary supplement (DS) by pupils in the exam period causes positive changes in their psychophysiological status, reduces the magnitude of sympathoadrenal system tension, and exerts an optimizing effect on the mechanisms responsible for regulation of the cardiovascular system. In this connection, in addition to other DSs, the above species may be recommended for use as a non-specific adaptogen under stress.

[Effects of licorice (Glycyrrhiza) roots in the rabbit feed on the tachycardiac effect of vibration].

During 30-day feeding with licorice (Glycyrrhiza) roots, further combined 30-day exposure to these roots and vibration prevents the formation of pronounced cardiac rhythm shifts, the emergence of the tachycardic effect of vibration and equilibrates the activity of autonomic mechanisms for cardiac regulation, as suggested by less pronounced changes in the vagosympathetic index.

[Impact of exercise on cardiac hemodynamic parameters in students].

Functional changes were studied in first-year students performing exercises. Analyzing the findings indicated that a 500-m race caused unidirectional varying changes in young women and young men. The functional systems of the first-year students responded to strenuous exercises due to the tension of cardiac rhythm regulatory mechanisms, which manifested itself as almost 4.5-fold increase in the activity of the sympathetic regulatory circuit. Excessive tension that was a result of long-term inactivity may be further a cause of disproportionally developed cardiac chambers, leading to myocardial hypertrophy, cardiac arrhythmia, weakened valvular apparatus.

[Changes of morphological indicators of blood from vibration and liquorice effect].

The effect of long-term exposure of vibration and feeding rabbits with liquorice (Glycyrrhiza glabra L) on peripheral blood indicators was studied. It was found that biological active substances of licorice accelerate metabolism processes of the marrow stem cells, enlarge organism compensatory abilities, in that way providing organism resistance to vibration.

[Change in salivary nitric oxide levels in students in the examinational period].

The influence of examination-induced psychoemotional stress on hemodynamic parameters and salivary nitric oxide (NO) levels was studied in students. Before examinations, the examinees with a sympathotonic response (75.0%) were observed to have diminished salivary NO excretion that was retained within 24-hours after an exam. There was a significant negative correlation between the amount of NO and the values of blood pressure. The examinees with a parasympathetic response (25%) were found to have elevated salivary NO levels with lowered blood pressures in the pre- and postexaminational periods.

[Cardiac rhythm in pupils during tests].

Variation pulsometry was used to study changes in the activity of cardiac rhythm regulating mechanisms in third-form pupils from a comprehensive school (a control group) and a gymnasium (a study group) under mental stress caused by the performance of mathematical tests. Two types of responses of the studied parameters: sympathetic (in the study group) and parasympathetic (in the control group), which were determined by the richness and intensity of an academic load and by the readiness of both categories of school-children, were identified.