Decrease In Sympathetic Activity Research Articles

Engagement of mental effort in response to mental fatigue: A psychophysiological analysis

Acute mental fatigue, characterized by a transient decline in cognitive efficiency during or following prolonged cognitive tasks, can be managed through adaptive effort deployment. In response to mental fatigue, individuals can employ two main behavioral patterns: engaging a compensatory effort to limit performance decrements, or disengaging effort, leading to performance deterioration. This study investigated the behavioral pattern used by participants in mental fatigue conditions. Fifty participants underwent a sequential-task protocol with counterbalanced sessions who took place in two separate sessions: a 30-min incongruent Stroop task (fatiguing session) or a 30-min documentary viewing task (control session), followed by a time-to-exhaustion (TTE) handgrip task at 13 % of maximal voluntary contraction. Psychophysiological measures included the preejection period, heart rate variability, blood pressure, and respiration. Behavioral results showed deteriorated TTE handgrip performance after the Stroop task compared to after the documentary viewing task. During the Stroop task participants were more conservative and prioritized accuracy over speed. Self-reported fatigue was greater after the Stroop task. Psychophysiological data revealed a gradual decrease in sympathetic activity over time in both tasks, with the Stroop task showing a more pronounced decrease. Taken together, these findings suggest a disengagement of effort for a large proportion of participants (49 %) that could be partly attributed to a habituation to the demands of the Stroop task. This study illustrates the interplay of behavioral patterns of effort investment in the context of mental fatigue and underscores the role of disengagement as a dominant response to this phenomenon among healthy participants.

Oscillation of Sympathetic Activity in Patients with Obstructive Sleep Apnea during the First Hour of Sleep.

(1) Background: Snoring is a cardinal symptom of obstructive sleep apnea (OSA) and has been suggested to potentially increase sympathetic activity. On the other hand, sleep itself usually leads to a decrease in sympathetic activity. Heart rate variability (HRV) analysis is a non-invasive technique used to assess autonomic nervous system function. However, there is limited research on the combined impact of sleep and snoring on sympathetic activity in individuals with OSA, particularly during the first hour of sleep (non-rapid eye movement sleep). The current study aims to investigate the net effect of sleep and snoring on sympathetic activity and explore factors that might contribute to increased sympathetic activity in individuals with OSA during the first hour of sleep. (2) Methods: The participants were referred from the outpatient department for OSA diagnosis and underwent whole-night polysomnography (PSG). Electrocardiogram (EKG) data from the PSG were downloaded for HRV analysis. HRV measurements were conducted in both the time and frequency domain, including the root mean square of successive differences between normal heartbeats (RMSSD) and the ratio of the absolute power of the low-frequency (LF) band (0.04-0.15 Hz) to the absolute power of the high-frequency (HF) band (0.15-0.4 Hz) (LF/HF ratio), respectively. (3) Results: A total of 45 participants (38 men and 7 women) were included in the analysis. The RMSSD gradually increased from 0-5 min to 50-60 min (p = 0.024), while the LF/HF ratio decreased (p < 0.001) during the first hour of sleep (non-rapid eye movement sleep). The LF/HF ratios of the "S" (snoring) episodes were compared with those of the pre-S episodes. An elevated LF/HF ratio during the S episode was associated with the first snoring episode occurring more than 20 min after lying down to sleep (Odds ratio, OR = 10.9, p = 0.004) and with patients diagnosed with severe OSA (OR = 5.01, p = 0.045), as determined by logistic regression. (4) Conclusions: The study observed an increase in the value of RMSSD and a decrease in the value of the LF/HF ratio during the first hour of sleep for patients with OSA. Higher LF/HF ratios were associated with the first occurrence of snoring while lying down for more than 20 min and with patients with severe OSA.

Microglia-Mediated Neuroimmune Response Regulates Cardiac Remodeling After Myocardial Infarction.

Background Sympathetic hyperactivity contributes to pathological remodeling after myocardial infarction (MI). However, the mechanisms underlying the increase in sympathetic activity remain unknown. Microglia are the predominant immune cells in the central nervous system and can regulate sympathetic neuron activity through neuroimmune response in the hypothalamic paraventricular nucleus. The present study aimed to investigate whether microglia-mediated neuroimmune response can regulate sympathetic activity and cardiac remodeling after MI. Methods and Results PLX3397 (pexidartinib) was used to deplete central microglia via intragastric injection or intracerebroventricular injection. After that, MI was induced by ligation of the left anterior descending coronary artery. Our study showed that MI resulted in the activation of microglia in the paraventricular nucleus. Microglia depletion, which was induced by PLX3397 treatment via intragastric injection or intracerebroventricular injection, improved cardiac function, reduced infarction size, and attenuated cardiomyocyte apoptosis, fibrosis, pathological electrical remodeling, and myocardial inflammation after MI. Mechanistically, these protective effects were associated with an attenuated neuroimmune response in the paraventricular nucleus, which contributed to the decrease of sympathetic activity and attenuation of sympathetic remodeling in the heart. However, intragastric injection with PLX3397 obviously depleted macrophages and induced neutrophil and T-lymphocyte disorders in the heart, blood, and spleen. Conclusions Microglia depletion in the central nervous system attenuates pathological cardiac remodeling after MI by inhibiting neuroimmune response and sympathetic activity. Intragastric administration of PLX3397 leads to serious deleterious effects in peripheral immune cells, especially macrophages, which should be a cause for concern in animal experiments and clinical practice.

ACE-Inhibitors in Hypertension: A Historical Perspective and Current Insights.

This review describes the discovery and development of ACE inhibitors as antihypertensive agents, compares their efficacy, tolerability, and safety to ARBs, and highlights the contemporary issues surrounding ACE inhibitor use for HTN. Angiotensin-converting enzyme (ACE) inhibitors are commonly prescribed medications for the management of hypertension (HTN) and other chronic conditions including heart failure and chronic kidney disease. These agents inhibit ACE, the enzyme that is responsible for converting angiotensin (AT) I to AT II. Inhibiting the synthesis of AT II causes arterial and venous vasodilation, natriuresis, and a decrease in sympathetic activity, resulting in the reduction of blood pressure. ACE inhibitors are first-line therapy in HTN management along with thiazide diuretics, calcium channel blockers, and angiotensin receptor blockers (ARB). Along with inhibiting AT II synthesis, inhibition of ACE causes accumulation of bradykinin, increasing the risk of bradykinin-mediated side effects like angioedema and cough. Since ARBs do not work on ACE in the renin-angiotensin system, the risk of angioedema and cough are lower with ARBs. Recent evidence has also suggested ARBs may have neuroprotective effects compared to other antihypertensives, including ACE inhibitors; however, this warrants further study. Currently, ACE inhibitors and ARBs have an equal class of recommendation for first-line treatment for the management of HTN. Recent evidence has shown ARBs to be just as effective as ACE inhibitors for HTN but with improved tolerability.

HIGH SALT INTAKE DID NOT DIMINISH BENEFICIAL EFFECT OF RENAL DENERVATION ON BLOOD PRESSURE, KIDNEY FUNCTION AND METABOLIC PROFILE - CROATIAN REAL-LIFE STUDY

Objective: Last trials clearly documented and confirmed the efficacy of renal denervation (RDN) on decrease of blood pressure (BP). Our aim was to analyze the effects of RDN beyond BP lowering in truly resistant hypertensive patients in real-life conditions. Design and method: Out of 31 truly resistant patients whose secondary forms of hypertension were ruled out and were enrolled into the Croatian Spyral RDN registry, 18(10 m, 8 w, average age 49.3) were eligible for analysis. Office BP, ABPM, central BP and PWV were measured with Omron M6, Mobilograph and Sphygmocor devices, respectively. Albuminuria and salt intake were determined from 24-h urine samples, eGFR using the CKD Epi equation. Sympathetic/parasympathetic activity was measured with an ANX-3.0 ANSAR device. All RDN procedures(Spyral Medtronic) were done by one physician (average number of ablation spots was 41/procedure). Patients were examined day before and that day, 1,3,6, and 12 months after the RDN. Reponse was drop of office systolic BP by 10 mmHg or more 6 months after RDN. There were no differences in the RDN procedure between responders and non-responders. Results: Office and ABPM values dropped the day after RDN and remained significantly lower at the end of the follow-up (6.5/-5.5 and -16.2/9 mmHg, respectively). The effect of RDN on BP was not abolished with high salt intake(15.5 g/day at the end of follow up). eGFR remained stable, and even slight improvement was observed at the end of follow-up(+8.4 ml/min/1.72m2); albuminuria significantly decreased (-115 mg/day). All metabolic parameters (lipids, uric acid) improved at the end of follow-up. LFa/RFa decreased the day after RDN and remained lower during the follow-up period. After RND central systolic BP and Aix decreased more in responders than in non-responders (-12.8 vs. -7.3; -7 vs. -2.6) while PP amplification was improved in responders (1.22 to 1.33) but decreased in non-responders (1.33 to 1.25). Conclusions: In real-life circumstances, BP significantly decreased after RDN despite large salt ingestion. eGFR and albuminuria improved as well as metabolic parameters at the end of follow-up and all of the beneficial changes run in parallel with observed decrease in sympathetic activity.

BLOOD PRESSURE VARIABILITY AND CIRCADIAN PATTERN AFTER RENAL DENERVATION - CROATIAN REAL-LIFE STUDY

Objective: Recent trials confirmed the lowering effect of renal denervation (RDN) on blood pressure (BP). We aimed to analyze the impact of RDN on BP variability and circadian rhythm. Design and method: Out of 31 truly resistant patients whose secondary forms of hypertension were ruled out and were enrolled into the Croatian Spyral RDN registry, 18 (10 m, 8 w, average age 49.3) were eligible for analyses. Office BP, ABPM, central BP, and PWV were measured with Omron M6, Mobilograph, and Sphygmocor devices. Sympathetic/parasympathetic activity was measured with ANX-3.0 ANSAR device. All RDN procedures (Spyral Medtronic) were done by one physician (average number of ablation spots was 41/procedure). Patients were examined the day before and that day, 1,3,6, and 12 months after the RDN. The response was a drop of office systolic BP by 10 mmHg or more 6 months after RDN. There were no differences in the RDN procedure between responders and non-responders. Results: Office and ABPM values dropped the day after RDN and remained significantly lower at the end of the follow-up (6.5/-5.5 and -16.2/9 mmHg, respectively). We failed to find changes in BP variability (SD) after RDN. However, a significant decrease in morning BP surge was observed immediately the day after RDN (-12.4) and was even lower at the end of the follow-up (-18.8 mmHg). Substantial number of patients who had an abnormal nocturnal BP pattern became dippers. Central systolic BP and PWV decreased (-6.3 mmHg and -0.72 m/s, respectively). LFa/RFa decreased the day after RDN and reminded lower during the follow-up period. After RDN morning BP surge remained stable and normal in responders; however, in non-responders, it decreased immediately after RDN (-21.2) and remained lower during the follow-up till the last visit (-33.3). Conclusions: Significant improvements in circadian rhythm and several parameters of central hemodynamics were observed after RDN indicating that RDN might be considered as a pathway to the complete, so-called perfect 24-hour BP control. Observed beneficial effects run in parallel with the observed decrease in sympathetic activity. Importantly, even in non-responders, RDN had a beneficial effect on morning BP surge.

Moderate-intensity aerobic exercise as an adjunct intervention to improve sleep quality among rotating shift nurses.

Nurses working rotating shifts (RS) are at risk of circadian rhythm disruption, which can affect sleep quality and can lead to emotional stress, anxiety, and depression. Aerobic exercise is a type of repetitive and structured physical activity that involves the metabolic system, which utilizes oxygen to produce energy and has been demonstrated to improve shift-workers' health and well-being. The main purpose of engaging in regular moderate-intensity aerobic exercise is to improve cardiopulmonary fitness and functional capacity. When engaging in moderate-intensity aerobic exercise, the increase in arterial pressure is accompanied by a simultaneous increase in heart rate, which signifi-cantly contributes to the rise in blood pressure, which is reversed after exercise due to an increase in parasympathetic activity and a decrease in sympathetic activity. Moderate-intensity aerobic exercise includes walking at a moderate pace, water aerobics, dancing, recreational swimming, gardening, table tennis, and stair climbing at a moderate pace and represents a cost-effective health promotion strategy for im-proving sleep quality and duration. Adherence to a moderate-intensity aerobic exercise program may increase both sleep quality and duration by improving melatonin concentrations, endocrine activities, heart rate and slow wave sleep among nurses working RS. Occupational medicine practitioners should consider creating a workplace health promotion program that incorporates moderate-intensity aerobic exercise for RS-nurses to minimize the impact of shift work on their sleep quality.

Neurophysiologic Reactions during Heart Rate Variability Biofeedback Session in Adolescents with Different Risk of Internet Addiction.

The aim of this study was to determine electroencephalogram (EEG) in a session of heart rate variability biofeedback (HRV BF) in adolescents with different Internet addiction (IA) risks. In total, 100 healthy adolescents aged 16–17 years with minimal risk of IA (Group I, 35%), pronounced risk of IA (Group II, 51%), and stable pattern of IA (Group III, 14%) using the Chen Internet Addiction Scale were examined. HRV and EEG parameters were determined at baseline (5 min), and then during the short-term HRV BF session (5 min), in order to increase the total power (TP, ms2) of the HRV spectrum. Against the background of an increase in the TP and a decrease in sympathetic activity, an increase in alpha EEG was revealed, especially in Groups I and II. The greatest increase in the power of beta1-activity of EEG in the frontal, central, and temporal brain regionswas found in Groups I and II. In adolescents with a pronounced risk of IA, HRV BF is accompanied by a severe activation of the brain systems, while in persons with a stable type of IA, the least brain reactivity is shown, especially in the beta1 EEG band.

Detection of Changes on Parameters Related to Heart Rate Variability after Applying Current Interferential Therapy in Subjects with Non-Specific Low Back Pain.

Interferential current therapy (ICT) is an electrotherapeutic intervention that combines the advantages of high permeability from middle frequency currents and efficient tissue stimulation from low frequency currents, delivering the maximum current with high tissue permeability. The aim was to evaluate the effects of ICT on heart rate variability (HRV) and on pain perception in patients with non-specific chronic low back pain (NSCLBP). In the study, 49 patients with NSCLBP were randomly divided into an experimental (EG) and a sham group (SG). All participants received a single intervention, ICT, or simulated intervention. Outcome measures including baseline (sit-down position) and postintervention (prone position) pain, heart rate (HR), time domain parameter (rMSSD), diameters of the Poincaré plot (SD1, SD2), stress score (SS), and sympathetic/parasympathetic (S/PS) ratio were investigated. In both groups, significant statistical differences were found in perceived pain and in all HRV parameters except in HRmax. Between-group comparisons showed statistically significant differences in all variables except for HRmin and HRmean in favor of the experimental group. These changes reported an increase in parasympathetic activity (rMSSD) (p < 0.05) and a decrease in sympathetic activity (increase in SD2 and decrease in SS) (p < 0.001) and perceived pain (p < 0.001), with a greater size effect (η2 = 0.44) in favor of the experimental group. In conclusion, a single session of ICT can shift the autonomic balance towards increase parasympathetic dominance and decrease the sympathetic dominance and intensity of pain perceived by patients with NSCLBP.

CARDIOHEMODYNAMIC RESPONSE TO LOCAL COLD EXPOSURE AMONG MEN FROM COASTAL- AND INLAND ZONES OF THE MAGADAN REGION

Aim: To study the changes in cardiodynamics experienced by humans under local cold exposure in coastal- and inland areas of the Magadan region, North-Eastern Russia. Methods: In total, 124 residents from the coastal area (Magadan) and 62 residents from the inland area (Susuman) took part in the experiment. Parameters of heart rate and hemodynamics at rest and at the peak of a cold test were estimated using "Varicard" device and a tonometer. Results: At rest the examinees from the continental zone demonstrated a less economical mode of the circulatory system functioning with a simultaneous decrease in sympathetic activity and the transition of the autonomic balance towards parasympathetic predominance. That is considered a regional-related feature of the functional status of the cardiovascular system when adapting to more extreme environmental factors. Such features of cardiohemodynamics could be observed against the background of an increase in basal metabolic rate by 17 % in subjects from Magadan and 31 % in those from Susuman. The short-term cold exposure caused a hypertensive response in both groups. The subjects from the continental area showed a more pronounced vasoconstriction, which was combined with a decrease in the activity of the parasympathetic link in the heart rhythm regulation, while the Magadan subjects demonstrated the opposite reaction to the cold test which led to the activation of the parasympathetic link of the ANS. Conclusion: The results that the residents of the coastal areas develop the reaction of getting used to the influence of the cold factor, with a slightly pronounced metabolic adaptation Young residents of the continental zone, in response to the effects of cold, develop an isolation type of cold adaptation with sufficient activation of metabolic adaptation.

Guanabenz inhibits alveolar bone resorption in a rat model of periodontitis

Increase of sympathetic activity has been known to exacerbate osteoporosis through promotion of bone resorption. However, it is largely unknown about involvement of sympathetic activity in exacerbation of periodontitis. In this study, we investigated whether α2-adrenergic receptor (α2-AR) agonist guanabenz which decreases sympathetic activity, attenuates alveolar bone resorption in rats having high sympathetic activity with periodontitis. Volumes of residual alveolar bone and attachment levels in periodontium were examined using micro-computed tomography and hematoxylin-eosin staining, respectively. Furthermore, osteoclast numbers per bone surface and osteoclast surface per bone surface were measured using tartrate-resistant acid phosphatase staining. To examine the suppressive effects of guanabenz on pro-inflammatory cytokines, expression levels of tyrosine hydroxylase (TH), TNF-α, IL1-β, and IL-6 in periodontium were measured using immunohistostaining. Administration of guanabenz attenuated loss of alveolar bone and attachment levels in rats having high sympathetic activity. Furthermore, its administration suppressed osteoclast numbers in rats having high sympathetic activity. TH, TNF-α, IL-1β, and IL-6 positive cells in periodontium in rats treated with guanabenz for 12 weeks, were lower than those in control rats having high sympathetic activity. This study demonstrated administration of α2-AR agonist guanabenz attenuates alveolar bone resorption through decrease of sympathetic activity in rats.

Comparing Ictal Cardiac Autonomic Changes in Patients with Frontal Lobe Epilepsy and Temporal Lobe Epilepsy by Ultra-Short-Term Heart Rate Variability Analysis.

Background and Objectives: Abnormal epileptic discharges in the brain can affect the central brain regions that regulate autonomic activity and produce cardiac symptoms, either at onset or during propagation of a seizure. These autonomic alterations are related to cardiorespiratory disturbances, such as sudden unexpected death in epilepsy. This study aims to investigate the differences in cardiac autonomic function between patients with temporal lobe epilepsy (TLE) and frontal lobe epilepsy (FLE) using ultra-short-term heart rate variability (HRV) analysis around seizures. Materials and Methods: We analyzed electrocardiogram (ECG) data recorded during 309 seizures in 58 patients with epilepsy. Twelve patients with FLE and 46 patients with TLE were included in this study. We extracted the HRV parameters from the ECG signal before, during and after the ictal interval with ultra-short-term HRV analysis. We statistically compared the HRV parameters using an independent t-test in each interval to compare the differences between groups, and repeated measures analysis of variance was used to test the group differences in longitudinal changes in the HRV parameters. We performed the Tukey–Kramer multiple comparisons procedure as the post hoc test. Results: Among the HRV parameters, the mean interval between heartbeats (RRi), normalized low-frequency band power (LF) and LF/HF ratio were statistically different between the interval and epilepsy types in the t-test. Repeated measures ANOVA showed that the mean RRi and RMSSD were significantly different by epilepsy type, and the normalized LF and LF/HF ratio significantly interacted with the epilepsy type and interval. Conclusions: During the pre-ictal interval, TLE patients showed an elevation in sympathetic activity, while the FLE patients showed an apparent increase and decrease in sympathetic activity when entering and ending the ictal period, respectively. The TLE patients showed a maintained elevation of sympathetic and vagal activity in the pos-ictal interval. These differences in autonomic cardiac characteristics between FLE and TLE might be relevant to the ictal symptoms which eventually result in SUDEP.

Pharmacogenetics as a Way for Personalizing Diuretic Therapy: Focus on Torasemide

Optimizing diuretic therapy in patients with chronic heart failure is a complicated problem with many unresolved questions. Diuretics take an important place in the treatment of heart failure, which are used in almost 80% of cases. Currently, there are not enough clinical studies, which comparative effectiveness of loop diuretics, as well as studies aimed at personalizing diuretic therapy. Torasemide has several advantages over other loop diuretics; high bioavailability, longer half-life and duration of action provide predictable diuresis. The presence of favorable neurohormonal effects, consisting in a decrease of sympathetic activity and inhibition of the renin-angiotensin-aldosterone system, leads to the fact that hypokalemia rarely occurs. In addition, torasemide slows development of myocardial fibrosis and fosters reverse ventricular remodelling. The use of personalization methods is one of the ways to increase the efficiency and safety of pharmacotherapy with diuretics. The polymorphism of genes encoding systems of biotransformation and transporters of drug is an important factor that determines the individual characteristics of a patient. Pharmacogenetics of torasemide may be of significant importance for pharmacokinetics and pharmacodynamics, influencing the intensity of the diuretic effect and side effects. The clearance of torasemide after oral administration may vary by 47% due to genetic characteristics: the participation of the OATP1B1 polymorphism is approximately 15.5%, the CYP2C9 polymorphism is 20%, and the OAT1 and OAT4 polymorphisms are 10%. Due to the significant differences in the pharmacokinetics of torasemide, further study of the pharmacodynamic characteristics of torasemide in patients with genetic polymorphism is necessary.

Effect of head down tilt on heart rate variability.

Context:Sirshasan is supposed to increase blood flow to the brain and considered to be beneficial for intellectual function, however mastering these techniques may be difficult.Aims:To see the effect of headstand using a tilt table on heart rate variability (HRV).Settings and Design:A cross-sectional study that was done on 26 healthy volunteers.Methods and Material:HRV was assessed in the supine position and 30° head tilt position for 5 min. HRV recording was done on the power lab (AD Instruments P Ltd, Castle Hill Australia). The tilt table used was Medica Podium, New Delhi, HLT-200.Statistical analysis used:Paired t-test.Results:All the HRV parameters showed non-significant change except low-frequency parameters which showed significant change during head tilt.Conclusions:Headstand to a 30° using tilt table cause a decrease in the autonomic activity which is mainly because of decrease in sympathetic activity.

Cardiovascular And Respiratory Responses During Aquatic Rehabilitation At Different Depths Of Supine Immersion

Aquatic Rehabilitation (AR), is used in the treatment of athletic injuries, initially in a supported supine aquatic position, before progressing to an independent vertical position. In water entry, cardiovascular and respiratory shifts are affected by, the hydrostatic pressure, the diving reflex responses, the water temperature, and vary at different positions and levels of immersion. PURPOSE: The purpose of this study was to investigate how the depth of submersion during AR at 32οC in a supine position, affects cardiovascular and respiratory function. METHODS: Seven participants (35±10 years), were subjected to two 15-min trials of AR aquatic bodywork manipulations (MKS). Subjects were supported in a supine position by the provider’s elbow under the head, and the trunk and lower legs, a) were either kept in alignment to the surface (SI) of the water with a lumbar curve support, or b) allowed to diagonally submerge to a deeper level (DI) during movements. An underwater video camera (FinepixGPS) was used for recording, and via 2-dimensional (2-D) kinematic analysis, the depth of submersion (LOGERPRO 3.8) and hydrostatic pressure, were evaluated. During the trials, respiratory rate (RR), heart rate (HR), and oxygen saturation (SO2) were measured (ApneaLink 1_218). Before and after the trials, arterial blood was drawn for gas analyses (Abbott-I-Stat) in addition to blood pressure determination. Trials were conducted in a randomized cross-over design and analyzed for dependent measures (p<0.05). RESULTS: The depth of submersion of the trunk and legs with the SI was 0.022±0.036 m versus 0.575±0.06 m with the DI. Significant differences were observed for RR, 14.42±2.29 breaths/min vs 11.34±2.42 breaths/min (p=0.03), and systolic blood pressure, 124.85±6.52 mmHg vs 109±7.00 (p=0.008), for SI and DI respectively. No significant differences were observed for oxygen saturation or any other arterial gas variables measured. CONCLUSIONS: The increase of the depth of submersion during AR significantly impacted select cardiorespiratory parameters, i.e. breathing frequency and systolic blood pressure, consistent with an increase in parasympathetic and/or decrease in sympathetic activity. Depending on pre-existing conditions this may affect the quality of clinical care during rehabilitation of the athlete.

922 - Low intensity shockwave therapy (LiST) may promote angiogenesis and alter α1/α2 adrenergic receptors ratio with decrease in sympathetic activity in the erectile tissue of naturally aged rats

922 - Low intensity shockwave therapy (LiST) may promote angiogenesis and alter α1/α2 adrenergic receptors ratio with decrease in sympathetic activity in the erectile tissue of naturally aged rats

Effects of low-intensity shock wave therapy (LiST) on the erectile tissue of naturally aged rats.

Low-intensity shock wave therapy (LiST) improves erectile function in patients with erectile dysfunction (ED), probably by promoting angiogenesis as suggested by studies on animals with comorbidities as disease associated ED models. We aim to investigate the effects of LiST on erectile tissue of healthy, naturally aged rats. Twelve naturally aged male rats were randomized into two groups: control group (n = 6) and LiST-treatment group (n = 6). Young rats (8 weeks) (n = 6) was also used as control. Each rat in treatment group received 300 shock waves with an energy flux density of 0.09 mJ/mm2 at 2 Hz. Sessions were repeated three times/week for 2 weeks, followed by a 2-week washout period. Real-time RT-PCR for the expressions of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), nerve growth factor (NGF), neuronal NOS (nNOS), as well as α1 and α2-adrenergic receptors (α1AR, α2AR) was performed, followed by immunohistochemical analysis (IHC) to evaluate protein expression. The expressions of VEGF, eNOS, and α2AR/α1AR ratio were increased after LiST (p = 0.039, p = 0.008, and p = 0.006 respectively). The increase of VEGF, eNOS, and α2AR was confirmed in IHC (p = 0.013, p = 0.092, and p = 0.096, respectively). The increase of VEGF and eNOS seem to play key role in the mechanism of action of LiST, apparently by inducing angiogenesis. The altered expression of α1/α2-adrenergic receptors could indicate a decrease in sympathetic activity. LiST showed to partially reverse changes associated with aging in erectile tissue of rats, which supports future research for ED prevention.

Esmolol indirectly stimulates vagal nerve activity in endotoxemic pigs

BackgroundThere is an increasing interest in beta-blockade as a therapeutic approach to sepsis following consistent experimental findings of attenuation of inflammation and improved survival with beta1 selective antagonist. However, the mechanism of these beneficial effects remains very uncertain. Thus, this study is aimed at investigating the effects of a beta-1 selective blockade on sympathetic/parasympathetic activity in endotoxin-challenged pigs using heart rate variability. The hypothesis is that an adrenergic blockade could promote parasympathetic activity. Indeed, the increase of parasympathetic activity is a mechanism recently described as beneficial in septic states.MethodsFifty-one endotoxin-challenged pigs were studied. After 30 min of endotoxin infusion and 30 min of evolution without intervention, the pigs were randomly assigned the placebo or esmolol treatment and were observed for 200 min. Overall heart rate variability was assessed continuously, in the temporal domain by standard deviation of RR intervals (SDNN, ms),and in the frequency domain by spectral powers of low frequency (LF, ms2 × 103/Hz) and high frequency (HF, ms2 × 103/Hz) bands.ResultsVariations of power in these frequency bands were interpreted as putative markers of sympathetic (LF) and parasympathetic (HF) activity. In LPS treated animals, Esmolol did not increase SDNN, but instead decreased LF and increased HF power.ConclusionThese spectral modifications associated to a beta-blocker treatment after an endotoxemic challenge are interpreted as a significant decrease of sympathetic activity and an indirect increase of vagal autonomic tone.

The effect of propofol when injected at different speeds for induction of general anesthesia: an observational study

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; The hypotensive effect of propofol is attributable to a decrease in sympathetic activity, direct vasodilatation and myocardial depression. The aim of the study was to assess the effect of propofol when injected at different speeds for induction of general anesthesia on the following parameters: blood pressure, time of induction of anesthesia, dose of propofol used.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; The present study was conducted in post Graduate Department of Anesthesia and Surgery, Govt. Medical College, Srinagar for a period of two years and included 90 patients from July 2014 to June 16, the study was prospective one.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; In our study patients divided into three groups with 30 patients in each group. The mean age in group P400, P600, P800 was statistically insignificant p&amp;gt;0.843.The mean weight in group P400, P600, P800 was statistically insignificant p&amp;gt;0.885.The mean height in group P400, P600, P800 was statistically insignificant p&amp;gt;0.748. The mean induction time in P400 and in P600 was statistically significant. The mean systolic blood pressure, pre and post induction in P400, in P600 and in group P800 was statistically significant. The mean diastolic blood pressure, in pre and post induction in P400, P600, P800 was statistically insignificant with a p&amp;gt;0.05. The mean arterial pressure in pre and post induction in P400, P600, P800 was statistically significant (p&amp;lt;0.05). The mean heart rate in pre and post induction was statistically insignificant. The mean oxygen saturation (%) pre and post induction was statistically insignificant.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;We concluded that induction dose required for loss of consciousness increased with a faster rate of infusion while time for induction was shorter in P800 compared to P400 and P600, and the decrease in mean blood pressure was less after induction in P400. Propofol injection should be slow enough to prevent any hemodynamic deterioration in anesthesia induction.&lt;/p&gt;

Current aspects of obstetrical and perinatal complications prevention in women with perinatal losses in history

The objective: to establish the features of heart rhythm autonomic regulation in mother and the fetus and their correlation with mother–placenta–fetus functional system in women with complicated obstetric anamnesis.Materials and methods. 97 pregnant women with perinatal losses in history were examined. The heart rate variability of mother and the fetus was evaluated using cardiointervalography. The standard methods were performed such as cardiotocography and ultrasound examination with doplerometry to study the fetus state. An early neonatal period was analised and the macroscopic and histological examination of the placenta was performed.Results. A study of heart rate variability revealed predominance of the sympathetic nervous system tone both during rest and during loading tests in women with complicated obstetric anamnesis (p&lt;0,05). Time characteristics of the fetus heart rate variability determined the desynchronization of neurohumoral regulation mechanisms with sympathetic hyperfunction as a result of reducing the adaptive capacity and metabolic–humoral effects on the cardiovascular system. Ultrasound signs of placental dysfunction in pregnant women with perinatal losses in history were reliably more often than in women from control group. Newborns from mothers with complicated obstetric anamnesis tend to have complicated early neonatal period (p&lt;0,05). Results of histological studies showed signs of placental dysfunction with a significant difference in main and control group.Conclusions. Women with complicated obstetric anamnesis have significant tension of the sympathetic nervous system with a fetus sympathetic activity decrease. This can testify the fetus energy reserves depletion and may be diagnosed at preclinical stage by cardiointervalography. The results of the histological study indicate the presence of placental dysfunction in most pregnant women with perinatal losses in history.