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This study aimed to assess the role of H2S in homocysteine-induced cardiodynamic effects in the isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique. The maximum and minimum rates of pressure in the left ventricle (dp/dt max, dp/dt min), systolic and diastolic left ventricular pressures (SLVP, DLVP), heart rate (HR), and coronary flow (CF) were measured. A spectrophotometrical method was used to measure the following oxidative stress markers: index of lipid peroxidation (thiobarbituric acid reactive substances, TBARS), nitrite level (NO2−), superoxide anion radicals (O2•−), and hydrogen peroxide (H2O2) concentrations. The administration of 10 µmol/l DL-homocysteine (DL-Hcy) alone decreased dp/dt max, SLVP, and CF but did not change any oxidative stress parameters. The administration of 10 µmol/l DL-propargylglycine (DL-PAG) decreased all cardiodynamic parameters and increased the concentration of O2•−. The co-administration of DL-Hcy and DL-PAG induced a significant decrease in all estimated cardiodynamic parameters and decreased the concentration of NO2− and O2•− but increased the levels of TBARS and H2O2. Homocysteine shows a lower pro-oxidative effect in the presence of hydrogen sulfide (H2S), which indicates a potential anti-oxidative capacity of H2S.

The high speeds achieved during the take-off, flight, and landing of modern aircraft present limitations for the visual system. The importance of maintaining visual function during these intervals has been recognized since the earliest stages of aviation development. Because of the great practical importance of air combat, research on visual stress during flight is of great importance receives much attention. Vision is the most important sensory function in terms of both flight safety and the quality performance of flight duties. Visual acuity of 12 Air Force pilots was investigated before and after exposure to + Gz acceleration in a human centrifuge. This centrifuge is a combination gravity and altitude apparatus, capable of reaching accelerations of up to 20 G and simulating altitudes of up to 30,000 m. Each pilot had individual centrifuge training, and individual skills were first stated measured at the first time of exposure to G acceleration, and again in a one week. The training level that corresponds corresponding to the improvement of individual skills during submission to Gz acceleration was applied. Exposure to +Gz acceleration provokes significant reactions and fluctuations in the eye. Immediately after exposure to + Gz acceleration, there was a transient decrease in visual acuity at a distance of 0.02 ± 0.04 degrees of visual angle. Pupil diameter increased from 3.5 ± 0.6 to 5.6 ± 0.5 mm. This dilation continued for 15 min following exposure to acceleration. Changes on the eye bottom were not noted. Previous work has shown that exposure to + Gz acceleration results in an increase in the depth of the eye chamber. Energy reserves in retinal tissue and the central nervous system allow continued operation of brain and visual systems to continue for a few seconds following interruption of blood supply to the head. This enables rapid tolerance to high G loads for a short period of time, usually approximately 5 seconds. At high initial rates of acceleration, significant changes in visual function can occur. However, the importance of maintaining visual acuity is increasing due to the application of novel functional displays for rapid orientation of the pilot in space, the configuration of the area field, aircraft opponents, and weapon systems. Therefore, it is necessary to continue studies that will provide accurate indicators of visual acuity in the context of real Gz acceleration and spatial disorientation.

Background: Cisplatin is one the most frequently used chemotherapeutic drugs for several decades. Although its antineoplastic effect has been reported in treatment of numerous malignances, various adverse effects seem to be the crucial limiting factor for its administration. Objective: Beside the most commonly described nephro- and hepatotoxicity, cisplatin therapy is also accompanied with gastrointestinal, reproductive, hematological, cardiovascular and neurological side effects. Since it has been reported that cisplatin induce oxidative damage in various tissues, it seems reasonable to investigate an antioxidant supplementation as potential therapeutical approach for attenuation of cisplatin toxicities. Methods: We performed a structured search of bibliographic databases for research literature using a focused review question and inclusion/exclusion criteria. The quality of retrieved papers (101 in total) was appraised using standard tools. Results: Numerous antioxidants (such as thiol compounds, polyphenols, vitamins, etc.) had been reported for their beneficial effects on cisplatin-induced cardiotoxicity. The effects of various antioxidants, including sulfur-containing amino acids, have also been explored for mitigation of cisplatin neurotoxicity. However, the results for antioxidant supplementation in reduction of cisplatin-induced toxicities are still to be applied in clinical trials. Conclusion: Considering the facts that sulfur-containing amino acids: (a) do not interfere with chemotherapeutics antitumor action; (b) do not exhibit any toxic effect (unless applied in dose several times above the recommended); and (c) produce significant protective effects on some cisplatin-induced toxicities connected to augmentation of oxidative damage - it seems that their administration can be harmless and protective supplementation against numerous adverse effects of certain antineoplastic agents.

Diabetes mellitus is a chronic condition that continues to increase in both incidence and prevalence. Renin–Angiotensin–Aldosterone System is one of the main modulators of chronic hyperglycaemia and, thus, its influence on tissues. Hyperglycaemia-induced oxidative stress is an important factor in diabetic cardiomyopathy. The present study was carried out on 24 adult male Wistar albino rats (8-week-old and with body masses of 190 ± 10 g). We evaluated the influence of acute administration of zofenopril on ex vivo myocardial function from rats with streptozotocin-induced diabetes mellitus, with a special emphasis on cardiodynamic and oxidative stress parameters in diabetic rat hearts. Rats were divided randomly into two groups (12 animals per group): control non-diabetic animals (C) were healthy rats perfused with 1.5 µM of zofenopril, and STZ-treated diabetic animals (DM) were diabetic animals perfused with 1.5 µM of zofenopril 4 weeks after the induction of diabetes. Our results demonstrated that diabetic rats are characterized by a depressed cardiac performance and that oxidative markers are related to alterations in cardiac function in rats with 4 weeks of STZ-induced diabetes. Additionally, the use of zofenopril as a monotherapy slightly diminished cardiac damage induced by chronic hyperglycaemia. However, long-term follow-up intervention trials are necessary to fully demonstrate the benefit of zofenopril in this context. A challenge for future investigations will be to identify the effects of chronic administration or combination therapy with angiotensin-converting enzyme inhibitors in various models of diabetes.

The aim of our study was to examine the effects of different dietary strategies, high-fat (HFd) or standard diet (Sd) alone or in combination with standardized oral supplementation (0.45 mL/kg/day) of Aronia melanocarpa extract (SAE) in rats with metabolic syndrome (MetS). SAE is an official product of pharmaceutical company Pharmanova (Belgrade, Serbia), however, the procedure for extraction was done by EU-Chem company (Belgrade, Serbia). Rats were divided randomly into six groups: control with Sd, control with Sd and SAE, MetS with HFd, MetS with HFd and SAE, MetS with Sd and MetS with Sd and SAE during 4 weeks. At the end of the 4-week protocol, cardiac function and liver morphology were assessed, while in the blood samples glucose, insulin, iron levels and systemic redox state were determined. Our results demonstrated that SAE had the ability to lower blood pressure and exert benefits on in vivo and ex vivo heart function. Moreover, SAE improved glucose tolerance, attenuated pathological liver alterations and oxidative stress present in MetS. Obtained beneficial effects of SAE were more prominent in combination with changing dietary habits. Promising potential of SAE supplementation alone or in combination with different dietary protocols in triggering cardioprotection should be further examined in future.

The role of N-methyl-D-aspartate receptor (NMDA-R) in heart is still unclear. For these ionotropic glutamate receptors is characteristic the necessity of both co-agonists, glutamate and glycine, for their activation, which primarily allows influx of calcium. The aim of the present study was to examine the effects of verapamil, as a calcium channel blocker, alone and its combination with glycine and/or glutamate on cardiac function, coronary flow, and oxidative stress in isolated rat heart or to examine the effects of potential activation of NMDA-R in isolated rat heart. The hearts of male Wistar albino rats were excised and perfused according to Langendorff technique, and cardiodynamic parameters and coronary flow were determined during the administration of verapamil and its combinations with glutamate and/or glycine. The oxidative stress biomarkers, including thiobarbituric acid-reactive substances, nitrites, superoxide anion radical, and hydrogen peroxide, were each determined spectrophotometrically from coronary venous effluent. The greatest decline in parameters of cardiac contractility and systolic pressure was in the group that was treated with verapamil only, while minimal changes were observed in group treated with all three tested substances. Also, the largest changes in coronary flow were in the group treated only with verapamil, and at least in the group that received all three tested substances, as well as the largest increase in oxidative stress parameters. Based on the obtained results, it can be concluded that NMDA-R activation allows sufficient influx of calcium to increase myocardial contractility and systolic pressure, as well as short-term increase of oxidative stress.

The aim of this study was to evaluate the effects of chronic NAC administration along with cisplatin on cisplatin-induced cardiotoxicity by means of coronary flow (CF), cardiodynamic parameters, oxidative stress markers and morphological changes in isolated rat heart. Isolated hearts of Wistar albino rats (divided into four groups: control, cisplatin, NAC and cisplatin+NAC group) were perfused according to Langendorff technique at constant coronary perfusion pressure starting at 50 and gradually increased to 65, 80, 95 and 110 cm H2O to evaluate cardiodynamic parameters within autoregulation range. Samples of coronary venous effluent (CVE) were collected for determination of CF and biochemical assays, and heart tissue samples for biochemical assays and histopathological examination. Cisplatin treatment decreased CF and heart rate, and increased left ventricular systolic pressure and maximum left ventricular pressure development rate. Cisplatin increased H2O2 and TBARS, but decreased NO2(-) levels in CVE. In tissue samples, cisplatin reduced pathological alterations in myocardium and coronary vessels, with no changes in the amount of total glutathione, as well as in activity of glutathione peroxidase and glutathione reductase. NAC coadministration, by reducing oxidative damage, attenuated cisplatin-induced changes of cardiodynamic and oxidative stress parameters, as well as morphological changes in myocardium and coronary vasculature.

For the past 40 years, anabolic-androgenic steroids have been used by a wide variety of athletes with the hope of improving their training, endurance, and performance. The aim of this study was to examine the chronic effects of nandrolone decanoate (20 mg/kg, s.c, Deca-Durabolin DECA(®)) on oxidative stress biomarkers in the hearts of sedentary and exercised rats. The male Wistar albino rats (n = 180, four groups with three subgroups, 15 per subgroup, age 10 weeks, body mass 200-220 g) were sacrificed, and in the collected samples of blood, the following markers of oxidative stress were measured spectrophotometrically: (1) index of lipid peroxidation (measured as TBARS-thiobarbituric acid reactive substances); (2) nitrites (NO2 (-)); (3) hydrogen peroxide (H2O2); (4) superoxide anion radical (O2 (-)), and superoxide dismutase, catalase, and glutathione reductase. The results clearly show that the impact of ND alone, or in combination with physical training in general, is mildly pro-oxidative. The chronic physical training probably induces the protective antioxidant enzyme system , which may be of clinical interest when faced with overdosage of this drug.

Connection between oxidative stress and clinical outcome in acute ischemic stroke (AIS) has been poorly investigated. This study was aimed to assess redox state (through measurement of oxidative stress markers) of patients with acute ischemic stroke during different stages of follow-up period, and to find association between values of mentioned markers and clinical outcome. The investigation was conducted on 60 patients (both sexes, aged 75.90 ± 7.37 years) who were recruited in intensive care units at the Special Hospital for Cerebrovascular Diseases "Sveti Sava," Belgrade. After verification of AIS, patients were followed up in four interval of time: (1) at admission, (2) within 24 h after AIS, (3) within 72 h after AIS, and (4) 7 days after AIS. At these points of time, blood samples were taken for determination of oxidative stress parameters [index of lipid peroxidation (measured as TBARS), nitric oxide (NO) in the form of nitrite ([Formula: see text]), superoxide anion radical ([Formula: see text]), hydrogen peroxide (H2O2)], and enzymes of antioxidant defense system [superoxide dismutase (SOD) and catalase (CAT)] using spectrophotometer. Present study provides new insights into redox homeostasis during ischemic stroke which may be of interest in elucidation of molecular mechanisms involved in this life-threatening condition. Particular contribution of obtained results could be examination of connection between redox disruption and clinical outcome in these patients. In that sense, our finding have pointed out that [Formula: see text] and NO can serve as the most relevant adjuvant biomarkers to monitor disease progression and evaluate therapies.

Objectives: To examine the effects of glycine, glutamate and their combination on cardiac function, coronary flow and oxidative stress in isolated rat hearts, and to examine the effects of potential activation of N-methyl-Daspartate (NMDA) receptors in isolated rat hearts. Methods: The hearts of male Wistar albino rats were excised and perfused according to the Langendorff technique, and cardiodynamic parameters (maximum rate of pressure development in the left ventricle [dp/dt max]; minimum rate of pressure development in the left ventricle [dp/dt min], systolic left ventricular pressure, diastolic left ventricular pressure, heart rate) and coronary flow were determined during the subsequent administration of glycine, glutamate and their combination. Oxidative stress biomarkers, including thiobarbituric acid-reactive substances, nitrites (NO2 −), superoxide anion radical (O2 −) and hydrogen peroxide (H2O2), were each determined spectrophotometrically in coronary venous effluent. Results: Treatment with glycine and glutamate alone did not cause a statistically significant change in any of the observed parameters; however, their combined administration induced significant decreases in dp/dt max, dp/dt min, heart rate and coronary flow compared with the control conditions. Treatment with glycine and glutamate together induced significant increases in NO2 −, O2 − and H2O2 levels. After the washout period, all parameters that had changed (cardiodynamic parameters, coronary flow and levels oxidative stress biomarkers) returned to values that were not significantly different from controls. Conclusions: The results of the present study indicate that NMDA receptors likely have important roles in the function of the heart and coronary circulation. In addition, these results are suggestive of a damaging effect of NMDA receptor overstimulation in heart functioning, potentially mediated by oxidative stress.

We have compared the cardiotoxicity of five platinum complexes in a model of isolated rat heart using the Langendorff technique. These effects were assessed via coronary flow (CF) and cardiac functional parameters. cis-Diamminedichloroplatinum(II) (cisplatin, CDDP), dichloro-(1,2-diaminocyclohexane)platinum(II) (Pt((II))DACHCl2), dichloro-(ethylenediamine)platinum(II) (Pt((II))ENCl2), tetrachloro-(1,2-diaminocyclohexane)platinum(IV) (Pt((IV))DACHCl4) and tetrachloro-(ethylenediamine)platinum(IV) (Pt((II))ENCl4) were perfused at increasing concentrations of 10(-8), 10(-7), 10(-6), 10(-5) and 10(-4) M during 30 min. In this paper, we report that cisplatin-induced dose-dependent effects on cardiac contractility and coronary flow both manifested as decrease in cardiac contractile force (dP/dt)max, heart rate and significant reduction in CF. Pt((II))ENCl2, Pt((IV))ENCl2 and Pt((IV))DACHCl4 did induce dose-dependent response only in case of CF. Our results could be also important for better understanding dose-dependent side effects of potential metal-based anticancer drugs.

In light of the limited data concerning the role of N-methyl-D-aspartate (NMDA) receptors in cardiac func- tion, the aim of the present study was to determine the role of NMDA receptors in cardiac function, as well as the possible role played by the oxidative stress induced by the over- stimulation of NMDA receptors in isolated rat heart. The hearts of male, Wistar albino rats (n = 24, 12 in each experimental group, BM 180-200 g) were retrogradely perfused at a constant perfusion pressure (70 cm H2O), using the Langendorff technique, and cardiodynamic parameters were determined during the subsequent administration of DL-homocysteine thiolactone (DL-Hcy TLHC) alone, the combination of DL-Hcy TLHC and dizocilpine (MK-801), and MK-801 alone. In the second experimental group, the order of the administration of each of the substances was reversed. The oxidative stress biomarkers, including thio- barbituric acid reactive substances (TBARS), NO2 - ,O 2 - and H2O2, were each determined spectrophotometrically. DL-Hcy TLHC and MK-801 depressed cardiac function. DL-Hcy TLHC decreased oxidative stress, a finding that contrasted with the results of the experiments in which MK- 801 was administered first. The findings of this study were suggestive of the likely role played by NMDA receptors in the regulation of cardiac function and coronary circulation in isolated rat heart.

Despite the widespread clinical use of cyclooxygenase (COX) inhibitors, dilemmas still exist about potential impact of these drugs on cardiovascular system. The present study was aimed to estimate the effects of different COX inhibitors (meloxicam, acetylsalicylic acid [ASA], and SC-560) on oxidative stress in isolated rat heart, with special focus on l-arginine/NO system. The hearts of male Wistar albino rats (total number n = 96, each group 12 rats, 8 weeks old, body mass 180–200 g) were retrogradely perfused according to the Langendorff technique at gradually increased perfusion pressure (40–120 cmH2O). After control experiments the hearts were perfused with the following drugs: 100 μmol/l ASA (Aspirin), alone or in combination with 30 μmol/l l-NAME, 0.3 μmol/l meloxicam (movalis) with or without 30 μmol/l l-NAME, 3 μmol/l meloxicam (alone or in combination with 30 μmol/l l-NAME), 30 μmol/l l-NAME, and administration of 0.25 μmol/l SC-560. In samples of coronary venous effluent the following oxidative stress markers were measured spectrophotometrically: index of lipid peroxidation (measured as thiobarbituric acid reactive substances [TBARS]), superoxide anion radical release (O2 −), and hydrogen peroxide (H2O2). While ASA was found to have an adverse influence on redox balance in coronary circulation, and coronary perfusion, meloxicam and SC-560 do not negatively affect the intact model of the heart. Furthermore, all effects were modulated by NOS inhibition. It seems that interaction between COX and l-arginine/NO system truly exists in coronary circulation, and can be one of the possible causes for achieved effects. That means: those effects induced by different inhibitors of COX are modulated by subsequent inhibition of NOS.

Considering the adverse effects of DL-homocysteine thiolactone hydrochloride (DL-Hcy TLHC) on vascular function and the possible role of oxidative stress in these mechanisms, the aim of this study was to assess the influence of DL-Hcy TLHC alone and in combination with specific inhibitors of important gasotransmitters, such as L-NAME, DL-PAG, and PPR IX, on cardiac contractility, coronary flow, and oxidative stress markers in an isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique at a 70 cm H2O and administered 10 μM DL-Hcy TLHC alone or in combination with 30 μM L-NAME, 10 μM DL-PAG, or 10 μM PPR IX. The following parameters were measured:dp/dtmax,dp/dtmin, SLVP, DLVP, MBP, HR, and CF. Oxidative stress markers were measured spectrophotometrically in coronary effluent through TBARS, NO2,O2-, and H2O2concentrations. The administration of DL-Hcy TLHC alone decreaseddp/dtmax, SLVP, and CF but did not change any oxidative stress parameters. DL-Hcy TLHC with L-NAME decreased CF,O2-, H2O2, and TBARS. The administration of DL-Hcy TLHC with DL-PAG significantly increaseddp/dtmax but decreased DLVP, CF, and TBARS. Administration of DL-Hcy TLHC with PPR IX caused a decrease indp/dtmax, SLVP, HR, CF, and TBARS.