Regulation Of Cardiovascular System Research Articles

Discovering novel targets of abscisic acid using computational approaches

Abscisic acid (ABA) is a crucial plant hormone that is naturally produced in various mammalian tissues and holds significant potential as a therapeutic molecule in humans. ABA is selected for this study due to its known roles in essential human metabolic processes, such as glucose homeostasis, immune responses, cardiovascular system, and inflammation regulation. Despite its known importance, the molecular mechanism underlying ABA's action remain largely unexplored. This study employed computational techniques to identify potential human ABA receptors. We screened 64 candidate molecules using online servers and performed molecular docking to assess binding affinity and interaction types with ABA. The stability and dynamics of the best complexes were investigated using molecular dynamics simulation over a 100 ns time period. Root mean square fluctuations (RMSF), root mean square deviation (RMSD), solvent-accessible surface area (SASA), radius of gyration (Rg), free energy landscape (FEL), and principal component analysis (PCA) were analyzed. Next, the molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) method was employed to calculate the binding energies of the complexes based on the simulated data. Our study successfully pinpointed four key receptors responsible for ABA signaling (androgen receptor, glucocorticoid receptor, mineralocorticoid receptor, and retinoic acid receptor beta) that have a strong affinity for binding with ABA and remained structurally stable throughout the simulations. The simulations with Hydralazine as an unrelated ligand were conducted to validate the specificity of the identified receptors for ABA. The findings of this study can contribute to further experimental validation and a better understanding of how ABA functions in humans.

Reinforcement learning for closed-loop regulation of cardiovascular system with vagus nerve stimulation: a computational study

Objective. Vagus nerve stimulation (VNS) is being investigated as a potential therapy for cardiovascular diseases including heart failure, cardiac arrhythmia, and hypertension. The lack of a systematic approach for controlling and tuning the VNS parameters poses a significant challenge. Closed-loop VNS strategies combined with artificial intelligence (AI) approaches offer a framework for systematically learning and adapting the optimal stimulation parameters. In this study, we presented an interactive AI framework using reinforcement learning (RL) for automated data-driven design of closed-loop VNS control systems in a computational study. Approach. Multiple simulation environments with a standard application programming interface were developed to facilitate the design and evaluation of the automated data-driven closed-loop VNS control systems. These environments simulate the hemodynamic response to multi-location VNS using biophysics-based computational models of healthy and hypertensive rat cardiovascular systems in resting and exercise states. We designed and implemented the RL-based closed-loop VNS control frameworks in the context of controlling the heart rate and the mean arterial pressure for a set point tracking task. Our experimental design included two approaches; a general policy using deep RL algorithms and a sample-efficient adaptive policy using probabilistic inference for learning and control. Main results. Our simulation results demonstrated the capabilities of the closed-loop RL-based approaches to learn optimal VNS control policies and to adapt to variations in the target set points and the underlying dynamics of the cardiovascular system. Our findings highlighted the trade-off between sample-efficiency and generalizability, providing insights for proper algorithm selection. Finally, we demonstrated that transfer learning improves the sample efficiency of deep RL algorithms allowing the development of more efficient and personalized closed-loop VNS systems. Significance. We demonstrated the capability of RL-based closed-loop VNS systems. Our approach provided a systematic adaptable framework for learning control strategies without requiring prior knowledge about the underlying dynamics.

Special aspects of the cardiovascular system regulation and cerebral blood flow under gravitational influences. Review (part 2)

This survey presents the material of neuroradiologic methods of investigation brain structures and function which changes during space flight. It’s taken to attention from inspection of cerebral blood circulation, reversibility of changes in the volumes of gray and white matter, features of neuroplasticity and the formation of new connectivity properties not previously discovered on Earth. The results of magnetic resonance imaging studies, changes in the balance of body fluids, indicators of the cardiovascular system under orthostatic testing, and features of the formation of blood circulation regulation during sleep, which is an integral component of adaptation to microgravity conditions, are presented.

Piezopulsometric analysis of the functional state of human cardiovascular system

This paper expounds how to apply in practice the developed computer method of arterial piezopulsometry, with examples, for non-invasive express analysis of the functional state and the nature of autonomic regulation of the cardiovascular system in patients of different ages and health conditions. The participation and role of the contractile component of myocytes of the left ventricle of the heart is assessed as a universal muscle effector, providing both the basic pumping function of the heart and the implementation of the autonomic regulation of heart contraction using peripheral neurohumoral mechanisms that maintain the optimal level of cardiac hemodynamics. This analysis enhances the predictive value of early non-invasive pulsometric diagnostics of the individual functional state and nature of regulation of human cardiovascular system during ontogenesis. This knowledge helps identify the risk of reducing the ability of the cardiovascular system, which has developed during its evolution, to maintain dynamic balance, self-regulation and adaptation to changing environmental conditions, which is associated with a violation of the body’s homeostasis.

Angiotensin-Converting Enzyme 2 Activation Is Not a Common Feature of Angiotensin-Converting Enzyme Inhibitory Peptides.

Angiotensin-converting enzyme (ACE) catalyzes the formation of angiotensin II (Ang II), a vasoconstrictor, whereas its homologue ACE2 degrades Ang II into angiotensin (1-7) (Ang (1-7)), a vasodilator. Given the similarities in structure and their interconnected roles in the regulation of cardiovascular system, this study aims to investigate if ACE-inhibitory (ACEi) peptides can also activate ACE2. About 200 potent ACEi peptides were subjected to molecular docking, 20 peptides were selected for cell and in vitro enzymatic activity studies, and 5 peptides were fed orally to spontaneously hypertensive rats at a dose of 15 mg/kg body weight/day for 7 days. Peptides IKW and RIY showed significant antihypertensive activity with activated circulating/aortic ACE2, circulating Ang (1-7), and decreased Ang II levels. IQY reduced blood pressure, increased Ang (1-7) level, but did not affect ACE and ACE2. Peptides MAW and MRW did not affect blood pressure, ACE, and ACE2. Our study showed that ACE2 activation is not a common feature of ACEi peptides.

On the possibility of non-invasive study of the peripheral mechanisms of autonomous regulation of the human cardiovascular system

The aim of this study was to evaluate the possibility of using the developed method of arterial piezopulsometry for non-invasive study of peculiarities of the functioning of peripheral mechanisms of autonomic regulation of the cardiovascular system in patients of different age and health state. Study emphasizes the importance of determining the variability of the parameters of blood pressure pulse waves as a measure of assessing the participation and role of the components of the neuroendocrine (sympatho-adrenal) efferent link in the formation of a fast and well-regulated response of systemic hemodynamics, using myocytes of the left ventricle of the heart as effectors. This paper discusses the possibility and expediency of personalized use of the arterial piezopulsometry method for pulsometric diagnostics of the functional state and nature of autonomic regulation of the functions of cardiovascular system in patients in order to be able to detect earlier pathological conditions and disorders of peripheral mechanisms that ensure adequate blood supply in humans.

A machine-learning algorithm integrating baseline serum proteomic signatures predicts exercise responsiveness in overweight males with prediabetes

The molecular transducers conferring the benefits of chronic exercise in diabetes prevention remain to becomprehensively investigated. Herein, serum proteomic profiling of 688 inflammatory and metabolic biomarkers in 36 medication-naive overweight and obese men with prediabetes reveals hundreds of exercise-responsive proteins modulated by 12-week high-intensity interval exercise training, including regulators of metabolism, cardiovascular system, inflammation, and apoptosis. Strong associations are found between proteins involved in gastro-intestinal mucosal immunity and metabolic outcomes. Exercise-induced changes in trefoil factor 2 (TFF2) are associated with changes in insulin resistance and fasting insulin, whereas baseline levels of the pancreatic secretory granule membrane major glycoprotein GP2 are related to changes in fasting glucose and glucose tolerance. A hybrid set of 23 proteins including TFF2 are differentially altered in exercise responders and non-responders. Furthermore, a machine-learning algorithm integrating baseline proteomic signatures accurately predicts individualized metabolic responsiveness to exercise training.

Outlook for ergometer testing with beat to beat blood pressure measurement

Objective. The article discusses the advantages of performing stress tests with pressure control at each heartbeat. The question of increasing accuracy, informativeness and safety of the test is considered. Materials and methods. We performed 30 bicycle ergometric tests with ECG measurement, beat to beat blood pressure measurement and periodic blood pressure measurement by the Korotkoff method in the shoulder. Results. It was shown that arterial pressure registered by Korotkoff sounds in the shoulder corresponded with continuous pressure at the registration moment. Because of the impossibility to measure the dynamics, the underestimation of maximum systolic arterial pressure by the Korotkoff method exceeds 20 mm Hg in every 3 tests, and exceeds 30 mm Hg in every 5 tests. Therefore, the beat to beat measurement of BP significantly improves the accuracy and informativeness value of stress tests. Conclusions. Continuous BP signal in the finger increases reliability of noisy Korotkoff sounds extraction and the results of BP measurement in the shoulder by the classical method. The increased accuracy and reliability of the measurement provides greater patient safety. Continuous pressure corrected by Korotkoff sounds during reference measurements in the shoulder gives a detailed and accurate picture of BP variations, which allows to investigate in detail features of the patient’s cardiovascular system regulation, both during and after the load, which is not available with classical BP measurement.

Quantification of Chromogranin A and Its Fragments in Biological Fluids.

Human chromogranin A (CgA), a 439-residue long neurosecretory protein, can serve as a circulating biomarker for a wide range of neuroendocrine tumors. Increased levels of immunoreactive CgA are also present in the blood of patients with cardiovascular, gastrointestinal, or inflammatory diseases with, in certain cases, important diagnostic and prognostic implications. A growing body of evidence suggest that CgA and various CgA-derived fragments have complex roles in the regulation of cardiovascular system, metabolism, innate immunity, angiogenesis, and tissue repair, sometime with opposite biological effects. For example, while full-length CgA (CgA1-439) inhibits angiogenesis, the CgA1-373 fragment, at certain doses, is proangiogenic. Thus, the selective quantification of CgA and its fragments in the blood of patients (and in other biological fluids) is of great experimental and clinical interest. Here, we describe methods to produce CgA1-439 and CgA1-373 and to develop ELISAs capable of detecting these polypeptides in a very selective manner. The same approach can be used, in principle, also for developing assays for other fragments.

Influence on the autonomic cardiovascular system regulation in the treatment of hypertension, arrhythmias and heart failure

Cardiovascular diseases are widespread and are the leading death cause in most countries, despite the creation and improvement of strategies to reduce cardiovascular risk. A significant role in the development and evolution of cardiovascular diseases belongs to sympathetic nervous system hyperactivity, and therefore the methods of effecting it are relevant for the prevention and treatment of cardiovascular pathology. The article discusses modern approaches to interventional and conservative regulation of the autonomic nervous system and neuromodulation in the prevention and treatment of hypertension, heart failure, tachyarrhythmias, as well as reflects a conjoint expert judgment on these issues.

Unconscious mind activates central cardiovascular network and promotes adaptation to microgravity possibly anti-aging during 1-year-long spaceflight

The intrinsic cardiovascular regulatory system (β, 0.00013–0.02 Hz) did not adapt to microgravity after a 6-month spaceflight. The infraslow oscillation (ISO, 0.01–0.10 Hz) coordinating brain dynamics via thalamic astrocytes plays a key role in the adaptation to novel environments. We investigate the adaptive process of a healthy astronaut during a 12-month-long spaceflight by analyzing heart rate variability (HRV) in the LF (0.01–0.05 Hz) and MF1 (0.05–0.10 Hz) bands for two consecutive days on four occasions: before launch, at 1-month (ISS01) and 11-month (ISS02) in space, and after return to Earth. Alteration of β during ISS01 improved during ISS02 (P = 0.0167). During ISS01, LF and MF1 bands, reflecting default mode network (DMN) activity, started to increase at night (by 43.1% and 32.0%, respectively), when suprachiasmatic astrocytes are most active, followed by a 25.9% increase in MF1-band throughout the entire day during ISS02, larger at night (47.4%) than during daytime. Magnetic declination correlated positively with β during ISS01 (r = 0.6706, P < 0.0001) and ISS02 (r = 0.3958, P = 0.0095). Magnetic fluctuations may affect suprachiasmatic astrocytes, and the DMN involving ISOs and thalamic astrocytes may then be activated, first at night, then during the entire day, a mechanism that could perhaps promote an anti-aging effect noted in other investigations.

The Role of microRNA in the Development, Diagnosis, and Treatment of Cardiovascular Disease: Recent Developments.

Since their discovery in 1993, microRNAs (miRNAs) have emerged as important regulators of many crucial cellular processes, and their dysregulation have been shown to contribute to multiple pathologic conditions, including cardiovascular disease (CVD). miRNAs have been found to regulate the expression of various genes involved in cardiac development and function and in the development and progression of CVD. Many miRNAs are master regulators fine-tuning the expression of multiple, often interrelated, genes involved in inflammation, apoptosis, fibrosis, senescence, and other processes crucial for the development of different forms of CVD. This article presents a review of recent developments in our understanding of the role of miRNAs in the development of CVD and surveys their potential applicability as therapeutic targets and biomarkers to facilitate CVD diagnosis, prognosis, and treatment. There are currently multiple potential miRNA-based therapeutic agents in different stages of development, which can be grouped into two classes: miRNA mimics (replicating the sequence and activity of their corresponding miRNAs) and antagomiRs (antisense inhibitors of specific miRNAs). However, in spite of promising preliminary data and our ever-increasing knowledge about the mechanisms of action of specific miRNAs, miRNA-based therapeutics and biomarkers have yet to be approved for clinical applications. SIGNIFICANCE STATEMENT: Over the last few years microRNAs have emerged as crucial, specific regulators of the cardiovascular system and in the development of cardiovascular disease, by posttranscriptional regulation of their target genes. The minireview presents the most recent developments in this area of research, including the progress in diagnostic and therapeutic applications of microRNAs. microRNAs seem very promising candidates for biomarkers and therapeutic agents, although some challenges, such as efficient delivery and unwanted effects, need to be resolved.

Anticipatory regulation of cardiovascular system on the emergence of auditory-motor interaction in young infants.

Humans develop auditory-motor interaction to produce a variety of rhythmic sounds using body movements, which are often produced and amplified with tools, such as drumming. The extended production of sounds allows us to express a wide range of emotions, accompanied by physiological changes. According to previous studies, even young infants enhance movements in response to auditory feedback. However, their exhibition of physiological adaptation on the emergence of auditory-motor interaction is unclear. We investigated the movement and cardiac changes associated with auditory feedback to spontaneous limb movements in 3-month-old infants. The results showed that infants increased the frequency of limb movements inducing auditory feedback, while they exhibited a more regular rhythm of the limb movements. Furthermore, heart rate increase associated with the limb movement was first inhibited immediately after the timing of the auditory feedback, which may reflect sustained attention to the auditory stimuli. Then, through auditory-motor experience, the heart rate increase was inhibited even prior to the auditory feedback, leading to suppression of the peak intensity of the heart rate increase. These findings suggest that young infants regulate the cardiovascular system as well as limb movements in anticipation of the auditory feedback. The anticipatory regulation associated with movement and attentional changes may contribute to reduced cardiovascular stress in auditory-motor interaction, and provide a developmental basis for more sophisticated goal-directed behavior of producing rhythmic sounds.

(Pro)renin Receptor Knockdown in Tyrosine Hydroxylase neurons in the PVN Protects Against the Development of HFD‐Induced Hyperglycemia and Increases Energy Expenditure in Mice

Type 2 diabetes mellitus (T2D) is the major form of human diabetes, accounting for approximately 90–95% of diagnosed diabetes cases in the United States. The brain renin‐angiotensin system (RAS), traditionally viewed as a cardiovascular regulatory system, has recently emerged as a critical part of metabolic and energy‐expenditure signaling systems in the central nervous system (CNS). The (pro)renin receptor (PRR) is a key component of the brain RAS and plays a pivotal role in the development of hypertension. However, its importance in high fat diet (HFD)‐induced metabolic physiology is not well understood. We recently showed that neuron‐specific PRR deletion (PRRKO) improves fasting blood glucose and glucose tolerance in mice under 16 weeks of HFD. However, the specific neuronal cell types and synaptic mechanisms by which PRR acts is largely unknown. Tyrosine Hydroxylase (TH)‐containing neurons are catecholaminergic neurons found in multiple regulatory nuclei throughout the brain. The TH neurons in the paraventricular nucleus (PVN, THPVN) have been previously implicated in metabolic and cardiovascular control via inhibition of brainstem regulatory nuclei. Accordingly, we hypothesize that PRR in THPVN neurons plays a critical role in the regulation of HFD‐induced hyperglycemia. To test this hypothesis, we injected both male and female TdTomato‐PRR‐LoxP mice with adeno‐associated virus serotype 2 (AAV2)‐mediated Cre‐recombinase driven by a rat TH promoter (AAV2‐TH‐Cre) to ablate PRR in the THPVN neurons (THPVNPRRKO). The Tdtomato‐LoxP mice received the same virus were used as control. Fasting blood glucose (FBG), glucose and insulin tolerance tests were performed to assess glucose handling and development of hyperglycemia following 6‐week HFD (60% calories from fat). Mouse metabolic parameters were measured over 48 hours in Sable Promethion metabolic cages with ad libitum access to HFD. In male mice, PRR‐LoxP mice had significantly higher FBG when compared with the THPVN PRRKO mice (144.1 ± 5.74 vs. 121.9 ± 4.34 mg/dl, P= 0.0059) at the end of the six week HFD treatment. Interestingly, PRR ablation in the THPVN did not improve FBG and glucose handling in female mice. Metabolic cage measurements revealed that THPVN PRRKO mice had elevated oxygen consumption (VO2, ml/minute/g body weight) (0.047 ± 0.009 vs. 0.043 ± 0.0008 P= 0.027) and carbon dioxide emission (VCO2, ml/minute/g body weight) (0.035 ± 0.0005 vs. 0.032 ± 0.0005, P=0.0125) versus control HFD‐fed mice over 48 hours, indicating enhanced metabolic rate. The energy expenditure was significantly higher (0.0125 ± 0.00017 vs 0.0116 ± 0.00014, kCal/Hr/g body weight P=0.0026) in the THPVN PRRKO mice compared with their control counterparts. Locomotor activity over 48 hours was similar between the two groups (59.94 ± 19.6 vs. 103.5 ± 42.42 total meters traveled, P=0.204), and no significant difference in food intake (0.254 ± 0.011 vs. 0.274 ± 0.012 g, P=0.090) or body weight (42.7 ± 3.65 vs. 43.6 ± 1.41 g, P=0.842) was observed. This data suggests that PRR knockout in THPVN neurons protects against glucose dysregulation and elevates energy expenditure in mice following HFD. We conclude that PRR THPVN neurons play a key regulatory role in glucose and metabolic regulation.

The height and LnLF power cover the most of sex differences during orthostasis

The sex differences in autonomic regulation of cardiovascular and respiratory system, as one of the key physiological mechanisms of disease, till now remain underexplored. We hypothesized that cardiovascular and respiratory systems share the same autonomic mechanisms, represented by heart rate variability (HRV) indexes, opposing the effect of orthostasis, which are partially different between sexes.The 147 participants, 78 men and 69 women were recruited from the student population of local University for the research study. The low and high frequency heart rate variability (LF and HF HRV) was computed from ECG recording in the sitting position for 5 minutes of resting and slow breathing (6 breaths per minute) stages. The sitting position was used according to requirement of spirometry system. The tidal volume (TV) and respiratory rate (RR) were recorded for one minute at the end of each stage. Systolic and diastolic blood pressure (SBP and DBP) were measured with automatic digital sphygmomanometer (OMRON EVOLV, Japan). Two‐way repeated measures MANOVA and MANCOVA (SPSS 22) were used to test for effects of orthostasis and sex on HR, SBP, DBP, HRV variables, TV, RR, and MV. Multiple stepwise regression analysis was used to determine predictors of cardiovascular and respiratory variables. Written informed consent was obtained from each participant.In the current study we found significant main effects of orthostasis on HR, DBP, LnLF, LnHF (P&lt;0.001 for each), and significant main effects of sex on HR, SBP, LnLF, TV, and MV (for HR P=0.004, for LnLF P=0.006, for the rest P&lt;0.001). Follow the significant sex by orthostasis interaction we found that RR increased only for men upon standing but not for women.Multiple stepwise linear regression analysis revealed that when adjusting for potentially confounding variables, the change of cardiovagal‐mediated LnHF power (Figure 1A) was an independent predictor of HR and RR response to orthostasis (Table 1, Models 1 and 2). Women was an independent predictor of dRR, while Women by dLnLF interaction determined dHR, showing that LnLF, indicating according to our hypothesis, baroreflex‐mediated sympathoinhibition, contribute to HR response in women (Fig. 1B).The BMI by LnLF power interaction was a negative predictor of resting RR (Table 1, Model 3). It is suggested that baroreflex‐mediated sympathoinhibition contribute to respiratory central pattern generator particularly in people with increased BMI. The same interaction was a positive predictor of TV (Table 1, Model 4) indicating that increased time of respiratory cycle accompines greater TV.The comparisons of the similar models with and without dummy variables indicating “Women”, revealed that the dummy variable replaced “Height” or “LnLF”, suggesting that differences in both independent variables relate to mechanisms controlling cardiorespiratory system specific to female gender.In conclusion, cardiovagal‐mediated LnHF HRV power controls both HR and RR and determines their response to orthostasis. The differences in height and LnLF power cover the most of the sex difference in mechanisms controlling cardiovascular and respiratory variables and their response to orthostasis.

Микроглия и предполагаемые макрофаги субфорникального органа: структурно-функциональные особенности

The subfornical organ is an important regulator of water-salt metabolism and energy balance of the body, involved in the control of the cardiovascular system and immune regulation. The organ comprises several cell populations, among which microglia and macrophages remain uncharacterized. This study aimed at structural, cytochemical, and functional characterization of microglia and macrophages of the subfornical organ in rats. Brain specimens were collected from mature male Wistar rats (n = 8). Microglia and macrophages were revealed by immunostaining with poly- and monoclonal antibodies against calcium-binding protein Iba1 and lysosomal protein CD68; the slides were examined by light and confocal laser microscopy. The study provides a comprehensive morphological characterization of microglial cells and macrophages of the subfornical organ. We demonstrate that the majority of Iba1-expressing cells in this area of the brain are microglial cells, not macrophages. Pre-activated state of the subfornical organ microglia may reflect structural and functional features of this organ and specific functions of local microglia. Subependymal microglial cells, the processes of which penetrate into the third ventricle of the brain, constitute a distinct subpopulation among the Iba1-expressing cells of the subfornical organ. Apart from microglial elements, the subfornical organ contains few tissue macrophages with characteristic strong expression of CD68 accompanied by undetectable or weak expression of Iba1.

Synchronization of the Processes of Autonomic Control of Blood Circulation in Humans Is Different in the Awake State and in Sleep Stages.

The influence of higher nervous activity on the processes of autonomic control of the cardiovascular system and baroreflex regulation is of considerable interest, both for understanding the fundamental laws of the functioning of the human body and for developing methods for diagnostics and treatment of pathologies. The complexity of the analyzed systems limits the possibilities of research in this area and requires the development of new tools. Earlier we propose a method for studying the collective dynamics of the processes of autonomic control of blood circulation in the awake state and in different stages of sleep. The method is based on estimating a quantitative measure representing the total percentage of phase synchronization between the low-frequency oscillations in heart rate and blood pressure. Analysis of electrocardiogram and invasive blood pressure signals in apnea patients in the awake state and in different sleep stages showed a high sensitivity of the proposed measure. It is shown that in slow-wave sleep the degree of synchronization of the studied rhythms is higher than in the awake state and lower than in sleep with rapid eye movement. The results reflect the modulation of the processes of autonomic control of blood circulation by higher nervous activity and can be used for the quantitative assessment of this modulation.

Influence of recovery means on the functional condition of the cardiovascular system of greek-roman style fighters at the stage of preliminary basic training

The ever-increasing competition among greco-roman wrestlers indicates the need to develop new tools and methods of sports training that would best meet the requirements set by the specifics of martial arts. Purpose: to determine the effectiveness of a set of restorative measures in greco-roman style wrestlers to improve their functional state of the cardiovascular system. Research methods: theoretical analysis of scientific and methodological literature, empirical: calculation of Kerdo index, study of heart rate, systolic blood pressure, diastolic blood pressure, stroke volume, minute volume of blood flow; pedagogical experiment, methods of mathematical statistics. In wrestlers at rest after the application of a set of restorative measures, the studied indicators of central hemodynamics were within normal limits, and after standard exercise a rational response of the cardiovascular system was noted, which was marked by an increase in heart rate by 31.10 beats per minute (p˂0.05), increase in systolic blood pressure - by 11.33 mm Hg (p˂0.05), decrease in diastolic blood pressure - by 1.50 mm (p˂0.05), increase in stroke volume - by 8,80 ml (p˂0.05) and minute blood volume - by 3.09 l / min (p˂0.05). Results: as a result of the conducted experimental research the positive influence and expediency of application of a complex of restorative measures for improvement of mechanisms of adaptation of cardiovascular system to physical activity was shown. Conclusions: The results of the study indicate that the developed set of restorative measures contributed to the normalization of the functional state of the cardiovascular system and autonomic regulation of greco-roman style fighters, as well as activation of compensatory and adaptive mechanisms of long-term adaptation.

Orthostatic test as an indicator of the state of the cardiovascular system and autonomic regulation of vascular tone

Purpose: to identify the influence of body length and various sports on the indicators of vascular regulation of students.&#x0D; Material and methods. The study involved 42 students who play sports at the amateur level, 18 of them are track and field’s sportsmen (short and medium distance running), 12 are football players, 12 are wrestlers. The number of students with a body length of more than 190 cm was 12 people. The number of students whose body length was 150-175 cm was 30 people. There were no students with a body length of 176-189 cm in the study. Following research methods were used in the work: method of analysis of literature sources; method of determining body length; orthostatic test method; method of determining stroke volume and minute blood volume; methods of statistical data processing (comparison of averages by the Student's method, multivariate analysis of variance).&#x0D; Results. The results of a more significant impact of judo and football in comparison with running short and medium distances on the indicators of vascular regulation: the best indicators - in judo, the next place - in football, then – in track and field sportsmen. It was found that students with a body length of more than 190 cm have difficulty with vegetative-vascular regulation.&#x0D; Conclusions. To improve the adaptive capacity of vascular regulation to change the position of the body from horizontal to vertical, it is effective to use any exercise, but the most effective exercises that activate aerobic and anaerobic glycolytic energy systems. In addition, exercises that require frequent transitions from lying (sitting) to standing positions, as well as changes in the direction of movement are useful.

Study of Circulating Apelin in Type 1 Diabetic Patients and its Association with Glycemic Control in a Group of Egyptian Population

Abstract Background Type 1 diabetes mellitus (T1DM) is one of the most common chronic and metabolic diseases worldwide. The incidence of T1DM is reported to be increasing by 3-5% per year, and the number of people with diabetes is estimated to reach 380 million by 2025. Several studies have shown that TIDM is associated with metabolic abnormalities and alteration of adipose tissue hormones (adipokines). Apelin, one of the most abundantly expressed adipocytokine, is a bioactive peptide and produces its effects through a cell surface G protein-coupled receptor called APJ.The apelinergic system, is involved in a wide range of functions including regulation of body fluid homeostasis, cardiovascular system, angiogenesis and energy metabolism . Additionally, apelin participates in pathological processes, including obesity and diabetes. Apelin plays a beneficial role in energy metabolism. Objectives The aim of this study is to evaluate serum Apelin levels in patients with type 1 diabetes and to correlate the serum Apelin level and glycemic control. Patients and Methods This study was a cross sectional study. Participants were classified into two groups. The first group included 60 patient with T1DM recruited from Ain Shams University Endocrinology and Diabetes outpatient clinics in Cairo during the period from June 2019 to January2002 and the second group included 40 healthy controls. Serum apelin (APLN), FBS, 2hrPP, HbA1c, lipid profile and eGDR were measured for each case. Results Comparison between T1DM patients and controls revealed that serum apelin levels, were significantly increased in cases compared to controls. Negative correlations were found between Apelin and HbA1c% in the diabetic group as a marker for glycemic control so apelin may have a promising role as biomarkers in T1DM. Conclusion Our study showed that apelin concentrations were increased in type 1 diabetic patients compared to healthy controls. The potential association of apelin with insulin secretion and action may reveal new pathways in the pathogenesis of type 1 diabetes. Apelin in T1DM patients may be considered as promising adipokines for predicting glycemic control.