Kardiorespiratorni fitnes i njegov značaj u reakcijama kortizola i laktata prilikom zimskih i letnjih marševa

Background: The influence of homeostatically regulated physiological processes, including cardiorespiratory fitness (VO2max), on the response to physical stressors such as acclimatisation and marching, remains understudied. We aimed to investigate the effects of summer and winter acclimatisation and marching on cortisol levels and blood lactate, to gain insight into the role of these physiological processes in the stress response. Methods: Two groups of young Europeans, classified as poor (PCF; n=9) and good physical condition (GCF; n=21), based on a VO2max threshold of 40 mL O2/ kg/min, underwent 2-h march (6–7 km/h) in winter (5 ∘C) and summer (32 ∘C). Commercial tests, UniCel DxI Access Cortisol assay and EKF Biosen Clinic/GP assay were used for cortisol and lactate blood measurements (morning samples and those taken immediately after marches), respectively. Results: Basal cortisol levels were significantly higher at 5 °C than at 32 °C (PCF group: P=0.0079; cortisol dropped after the march at 5 °C in both groups, but increased at 32 °C only in PCF. Basal lactate levels were higher at 32 °C only in the GCF group (compared to PCF, P=0.0014) and post-marching (compared to basal values, P=0.0002). Conclusion: Cold exposure elicits a more significant stress response, based on higher basal cortisol levels, in individuals with worse physical fitness. Anaerobe metabolism prevails in participants with better physical fitness exposed to high ambient temperature based on increased basal and post-marching lactate levels. The study is significant for individual training/performance optimisation as it indicates the association between physiological stress responses and individual physical fitness levels.Uvod: Uticaj homeostatski regulisanih fiziolo{kih procesa, uklju~uju}i kardiorespiratornu kondiciju (VO2max), na odgovor na fizi~ke stresore poput aklimatizacije i mar{i- ranja, ostaje nedovoljno prou~en. Cilj istra`ivanja je bio i da se ispita uticaj aklimatizacije i mar{iranja tokom leta i zime na nivoe kortizola i laktoze u krvi, pru`aju}i uvid u ulogu ovih fiziolo{kih procesa u odgovoru na stres. Metode: Dve grupe mladih Evropljana, klasifikovane kao osobe sa slabom (PCF; n=9) i dobrom fizi~kom kondicijom (GCF; n=21), na osnovu praga VO2max od 40 mL O 2/kg/min, su bile izlo`ene dvosatnom mar{u (6–7 km/h) u dva navrata, zimi na 5 °C i leti, na 32 °C. U uzorcima krvi (jutarnji i neposredno nakon mar{a) su odre|ivani nivoi kortizola i laktata komercijalnim testovima, UniCel DxI Access Cortisol i EKF Biosen Clinic/GP. Rezultati: Bazalni nivoi kortizola su bili zna~ajno vi{i na 5 °C nego na 32 °C (u PCF grupi: P=0,0079); nakon mar{i- ranja na 5 °C kortizol opada u obe grupe a pove}an je na 32 °C samo u PCF grupi. Bazalni nivoi laktoze bili su vi{i na 32 °C samo u GCF grupi (porede}i sa PCF grupom, P=0,0014) i nakon mar{iranja (porede}i sa bazalnim vred- nostima, P=0,0002)

The Effects of DPP4 Inhibitors on Lipid Status and Blood Pressure in Rats with Diabetes Mellitus Type 2

The aim of the present study was to examine, evaluate and compare the effects of administered dipeptidyl peptidase-4 (DPP4) inhibitors saxagliptin and sitagliptin on lipid status parameters and blood pressure in rats with streptozotocine induced diabetes mellitus type 2. Forty-eight Wistar albino rats were divided randomly into 4 groups: 1. group I: control healthy group; 2. group II: rats with diabetes mellitus type 2; 3. group III: rats with diabetes mellitus type 2+ treated with 0.6 mg/kg of sitagliptin; 4. group IV: rats with diabetes mellitus type 2 treated with 0.45 mg/kg of saxagliptin. The rats from experimental groups were fed with a high-fat diet for 4 weeks and after 6–8 h of starvation received one dose of streptozotocin (STZ) intraperitoneally (25 mg/kg body weight) to induce type 2 diabetes mellitus (T2DM). Animals with fasting glucose above 7 mmol/L and insulin over 6 mmol/L were included in the study as rats with T2DM. Upon completion of the experiments, the blood was collected from the anesthetized animals and serum triglyceride (TG), total cholesterol (TCH), high density lipoprotein (HDL), and low density lipoprotein (LDL) were measured using spectrophotometry and commercial kits. At the beginning of the study and the day before sacrificing animals, the blood pressure and heart rate were measured by a tail-cuff noninvasive method. DPP4 inhibitors, as glucagon-like peptide-1 (GLP-1) agonists, were associated with modest reductions in DBP, LDL-C, TCH, and TGL and significant improvement in HDL, SBP and HR

The Effect of the Chronic Administration of DPP4-Inhibitors on Systemic Oxidative Stress in Rats with Diabetes Type 2

Type 2 diabetes (T2DM) is characterized by well-preserved insulin secretion; however, the surrounding tissue is insensitive to insulin, resulting in increased blood glucose level due to the inability of tissues to convert glucose into energy. As a result of chronic non-regulation of glucose levels and high daily fluctuations in the blood, the micro- and macrovascular complications occur in these patients. Complications develop through two main mechanisms: induction of oxidative stress and innate immunity. In this regard, the aim of this study was to examine the effect of four week administration of DPP4 inhibitors (saxagliptin, sitagliptin and vildagliptin) to the parameters of oxidative stress and antioxidant defense in the group of rats with diabetes type 2 (T2DM). Sixty Wistar albino rats were divided randomly into 5 groups: group I: control healthy group; group II: rats with diabetes type 2; group III: rats with diabetes type 2 treated with 0.6 mg/kg of sitagliptin; group IV: rats with diabetes type 2 treated with 0.45 mg/kg of saxagliptin, group V: rats with diabetes type 2 treated with 9 mg/kg vildagliptin. The rats from experimental groups were fed with a high-fat diet for 4 weeks and after 6–8 h of starvation received one dose of streptozotocin (STZ) intraperitoneally (25 mg/kg body weight) to induce T2DM. Animals with fasting glucose above 7 mmol / L and insulin over 6 mmol / L were included in the study as rats with T2DM. Upon completion of the experiments, the blood was collected from the anesthetized animals and used for sphectrophotometrical determination of parameters of oxidative stress, and antioxidative defense. T2DM induced significant increase in production of reacitve oxygen species (ROS) (superoxide anion radical and hydrogen peroxide), but additional four-week administration of gliptins induced decrease in ROS values. On the other hand, T2DM induced decrease of nitric oxide, superoxide dismutase, catalaze, and reduced gluthation and concomitant therapy with gliptins induced increase of these parametars, suggesting significant antioxidant potential of this group of drugs

The Effects of N-Methyl-D-Aspartate Receptor Blockade on Oxidative Status in Heart During Conditioning Maneuvers

N-methyl-D-aspartate receptor (NMDAR) belongs to iono-tropic glutamate receptor family. The most prominent roles of the NMDAR are related to the physiological and pathophysiological processes of the central nervous system (CNS). The link between NMDAR and cardiovascular pathology came into focus due to detrimental effects of homocysteine on the cardiovascular system. Regarding the fact that NMDAR affects Ca2+ homeostasis in cells, one of the main mechanisms which mediate adverse effects of glutamate dyshomeostasis and abnormal NMDAR activity is oxidative stress. Both in ischemia and during reperfusion, there are imbalance in Ca2+ and production of reactive species, which remains one of the basic mechanisms underlining the overall cardiomyocyte death due to myocardial infarction. The aim of this study was to assess the effects of blockade of NMDAR in heart using MK-801, in preconditioning and postconditioning fashion and to compare the values of oxidative stress biomarkers. We used Langendorff technique of isolated heart. In the control group, all isolated rat hearts were subjected to global ischemia after stabilization period (perfusion of the whole heart with Krebs-Henseleit solution was stopped) for 20 minutes, followed by 30 minutes of reperfusion. In the preconditioning group, after stabilization period, hearts were perfused with MK-801 for 5 minutes, before global ischemia of 20 minutes which was followed by 30 minutes reperfusion. In the postconditioning group, hearts were perfused with MK-801 during the first 3 minutes of reperfusion. Results of this study showed antioxidative effects of NMDAR inhibition in pre- and postconditioning of the isolated rat heart

The influences of chokeberry extract supplementation on redox status and body composition in handball players during competition phase

The aim of our study was to investigate the influence of 12 weeks of consumption of chokeberry extract on redox status, body composition, lipid profile, and biochemical parameters in active handball players. The study included 16 handball players aged 16–24 years (20.26 ± 2.86 years). Every morning before training, players received 30 mL of liquid chokeberry extract for 12 weeks during the regular competition season. The research consisted of morphofunctional and biochemical testing, which was performed at three points (at the beginning of the study and at 6 and 12 weeks after extract consumption). After the chokeberry extract treatment, we observed significant changes in three main aspects. The 12 week supplementation with chokeberry extract decreased the levels of prooxidants (TBARS and nitrites) and increased catalase activity. Analyzing the dynamic of body composition showed a decrease in body fat (9.4 ± 0.5 vs. 7.3 ± 0.6 kg) as well as its percent in a body (11.4 ± 0.4% vs. 8.8 ± 0.4%). On the other hand, the analysis showed an increase of high-density lipoprotein (1.3 ± 0.3 vs. 1.6 ± 0.2 mmol/L) and hemoglobin (144.4 ± 11.7 vs. 151.7 ± 9.9 g/L) after 6 weeks of treatment. At the same time, a decrease in leukocytes (7.2 × 109 ± 2.8 vs. 6.5 ± 1.2 × 109/L) and an increase in red blood cells count (4.9 ± 0.4 × 109 vs. 5.5 ± 0.5 × 109/L) were observed. Overall, these results emphatically show that the use of chokeberry extract dietary supplement induced a wide range of beneficial effects in the examined group of athletes.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Gas Transport Characteristics of Hemocorrectors and Perfusates Based on Perfluorocarbon Blood-Substituting Emulsions

This review summarizes the data regarding the gas transport characteristics of hemocorrection and perfusates on the basis of low concentrated drugs nano-sized perfluorocarbonic 20% Perftoran (a blood substitute, it is allowed for clinical use in Russia), 20% Ftoremulsion III (an improved blood substitute, registered in Russia), 10-20% Perfusol (a perfusion solution for perfusion of the isolated heart), 20% Ftorem (a cardioplegic emulsion for surgeries on the stopped heart) used in the biomedical field. The compensation of blood loss using traditional plasma substitutes without the gas transport function or with low gas transport characteristics leads to a decrease in the oxygen capacity of the resulting mixture and subsequently to deterioration in the oxygen transport characteristics of blood. The synthetic gas-transport blood substitutes can be used in the treatment of various forms of ischemia, such as carbon monoxide poisoning. Furthermore, recent results regarding the mechanism of COVID19 infection indicate a possible use of the synthetic gas-transport blood substitutes in the treatment and therapy of COVID19 infected patients

Short-Term Administration of Lemon Balm Extract Ameliorates Myocardial Ischemia/Reperfusion Injury: Focus on Oxidative Stress

We aimed to investigate the cardioprotective effects of ethanolic Melissa officinalis L. extract (ME) in the rat model of myocardial ischemia/reperfusion (I/R) injury. Thirty-two Wistar rats were randomly divided into a CTRL non-treated control group with myocardial I/R injury and three experimental groups of rats treated with 50, 100, or 200 mg/kg of ME for 7 days per os. Afterward, hearts were isolated, and cardiodynamic function was assessed via the Langendorff model of global 20 min ischemia and 30 min reperfusion. Oxidative stress parameters were determined spectrophotometrically from the samples of coronary venous effluent (O2−, H2O2, TBARS, and NO2−,) and heart tissue homogenate (TBARS, NO2−, SOD, and CAT). H/E and Picrosirius red staining were used to examine cardiac architecture and cardiac collagen content. ME improved cardiodynamic parameters and achieved to preserve cardiac architecture after I/R injury and to decrease fibrosis, especially in the ME200 group compared to CTRL. ME200 and ME100 markedly decreased prooxidants TBARS, O2−, and H2O2 while increasing NO2−. Hereby, we confirmed the ME`s ability to save the heart from I/R induced damage, even after short-term preconditioning in terms of preserving cardiodynamic alterations, cardiac architecture, fibrosis, and suppressing oxidative stress, especially in dose of 200 mg/kg

Sacubitril/valsartan in Heart Failure and Beyond—From Molecular Mechanisms to Clinical Relevance

As the ultimate pathophysiological event, heart failure (HF) may arise from various cardiovascular (CV) conditions, including sustained pressure/volume overload of the left ventricle, myocardial infarction or ischemia, and cardiomyopathies. Sacubitril/valsartan (S/V; formerly termed as LCZ696), a first-in-class angiotensin receptor/neprilysin inhibitor, brought a significant shift in the management of HF with reduced ejection fraction by modulating both renin-angiotensin-aldosterone system (angiotensin II type I receptor blockage by valsartan) and natriuretic peptide system (neprilysin inhibition by sacubitril) pathways. Besides, the efficacy of S/V has been also investigated in the setting of other CV pathologies which are during their pathophysiological course and progression deeply interrelated with HF. However, its mechanism of action is not entirely clarified, suggesting other off-target benefits contributing to its cardioprotection. In this review article our goal was to highlight up-to-date clinical and experimental evidence on S/V cardioprotective effects, as well as most discussed molecular mechanisms achieved by this dual-acting compound. Although S/V was extensively investigated in HF patients, additional large studies are needed to elucidate its effects in the setting of other CV conditions. Furthermore, with its antiinflamatory potential, this agent should be investigated in animal models of inflammatory heart diseases, such as myocarditis, while it may possibly improve cardiac dysfunction as well as inflammatory response in this pathophysiological setting. Also, discovering other signalling pathways affected by S/V should be of particular interest for basic researches, while it can provide additional understanding of its cardioprotective mechanisms

Examining the Effects of Hyperbaric Oxygen Therapy on the Cardiovascular System and Oxidative Stress in Insulin-Treated and Non-Treated Diabetic Rats

Background: This study explored the effects of hyperbaric oxygen therapy (HBOT) on the cardiovascular system and oxidative stress in streptozotocin-induced diabetic rats. Wistar albino rats were divided into four groups: DM group (diabetic rats), DM+HBOT group (diabetic rats exposed to HBOT for 1 h daily, five days a week, at 2.8 atmosphere absolute (ATA) with 100% oxygen for two weeks), DM+INS group (diabetic rats treated with neutral protamine hagedorn (NPH) insulin at a dosage of 3–5 U/day), and DM+HBOT+INS group (diabetic rats treated with both NPH insulin and HBOT for two weeks). Methods: Evaluations included glycemic control, oxidative stress parameters, and cardiac function measurements. Results: NPH insulin treatment reduced blood glucose levels, although normoglycemia was not achieved. The DM+HBOT+INS group demonstrated the lowest pro-oxidative marker levels. NPH insulin treatment improved cardiac function, and combination therapy effectively restored cardiac function in diabetic animals. Conclusions: NPH insulin treatment reduced hyperglycemia and improved cardiac function in diabetic rats. The combined approach of NPH insulin and HBOT resulted in decreased pro-oxidative markers. These findings provide valuable insights for managing cardiovascular complications and oxidative stress in diabetes

Antioxidative Effects of Standardized <i>Aronia melanocarpa</i> Extract on Reproductive and Metabolic Disturbances in a Rat Model of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) represents the most common endocrinopathy among childbearing-age women, with oxidative stress (OS) underlying its etiopathogenesis. Metformin (MET) represents a frequently used agent in PCOS. However, weak results encourage alternative treatments. We aimed to investigate isolated and synergistic effects of Standardized Aronia melanocarpa extract (SEA) and MET for alleviating reproductive and metabolic PCOS abnormalities. PCOS induction was followed by 28-day treatment with MET, SAE, or MET + SEA. Bodyweight (BW), cyclicity, histological, and ultrasonographical ovarian analyses were performed. Hormonal, glycemic, and lipid profiles were accessed, as well as systemic and ovarian oxidative status; BW, cyclicity, ovarian histomorphology, ovarian volume, testosterone and progesterone levels, as well as LDL, triglycerides, and total cholesterol levels were aggravated after PCOS-induction and improved after MET, SEA, and MET + SEA treatment. MET + SEA had the greatest impact on glycoregulation. Alterations in OS parameters (TBARS, O2−, H2O2, catalase, superoxide dismutase, and reduced glutathione) could be responsible for observed differences; (4) Conclusions: Our findings confirmed that SAE alone or along with MET was capable of ameliorating reproductive and metabolic disturbances in the PCOS rat model, with the restoration of OS parameters. SAE alone did not alter the protective effects of MET in PCOS