Horner syndrome: A new hypothesis for signaling pathway of enophthalmos sign

The Article Abstract is not available.  

Not just sensitization: sympathetic mechanisms contribute to expand experimental referred pain

Background

Widespread pain partially depends upon sensitization of central pain mechanisms. However, mechanisms controlling pain distribution are not completely known. The present study sought to assess skin temperature variations in the area of experimentally-induced pain and potential sex differences.

Methods

Pressure-pain thresholds (PPTs) were measured on the right infraspinatus muscle. At the end of Day 0, all participants performed an eccentric exercise of the shoulder external rotators to induce muscle soreness 24 hours after. On Day 1, participants indicated on a body chart the area of pain induced by 60 seconds of suprathreshold pressure stimulation (STPS; PPT + 20%) on the right infraspinatus muscle. Skin temperature variations in the area of referred pain were recorded with an infrared thermography camera, immediately before and after the STPS.

Results

Twenty healthy, pain-free individuals (10 females) participated. On Day 0, the pre-STPS temperature was higher than the post-STPS temperature on the arm (P = 0.001) and forearm (P = 0.003). On Day 1, the pre-STPS temperature was higher than the post-STPS temperature on the shoulder (P = 0.015), arm (P = 0.001), and forearm (P = 0.010). On Day 0, the temperature decrease after STPS in females was greater than in males on the forearm (P = 0.039). On Day 1, a greater temperature decrease was found amongst females compared with males at the shoulder (P = 0.018), arm (P = 0.046), and forearm (P = 0.005).

Conclusions

These findings indicate that sympathetic vasomotor responses contribute to expand pressure-induced referred pain, especially among females.

Differences in stress system (re-)activity between single and dual- or multitasking in healthy adults: A systematic review and meta-analysis

AbstractIn the age of digitization, multitasking requirements are ubiquitous, especially in the workplace. Multitasking (MT) describes the activity of performing multiple (at least two) tasks at the same time. Dual tasking (DT) refers to the sequential switching between two tasks. The aim of our systematic review and meta-analysis was first to investigate whether physiological stress systems become activated in response to or during MT/DT and, secondly, whether this (re-)activity is higher compared to single tasking. We focused on the Sympathetic Nervous System (SNS), the Parasympathetic Nervous System (PNS), the hypothalamic-pituitary adrenal (HPA) axis, and the immune system. The systematic review has been pre-registered with PROSPERO (CRD42020181415). A total of twenty-five articles were identified as eligible, in which n = 26 studies were reported, with N = 1,142 participants. Our main findings are that SNS activity is significantly higher and PNS activity is significantly lower during MT/DT than during single tasking. Only two studies were found, in which HPA axis (re-)activity was surveyed. No eligible study was identified in which immune system (re-)activity was investigated. This is the first systematic synthesis of the literature base showing that stress system activity is increased during MT/DT in comparison to single-tasking.

Developmental Consequences of Early Life Stress on Risk for Psychopathology: Longitudinal Associations with Children's Multisystem Physiological Regulation and Executive Functioning

The etiology of psychopathology is multifaceted and warrants consideration of factors at multiple levels and across developmental time. Although experiences of adversity in early life have been associated with increased risk of developing psychopathology, pathways toward maladaptation or resilience are complex and depend upon a variety of factors, including individuals' physiological regulation and cognitive functioning. Therefore, in a longitudinal cohort of 113 mother-child dyads, we explored associations from early adverse experiences to physiological co-regulation across multiple systems and subsequent variations in executive functioning. Latent profile analysis derived multisystem profiles based on children's heart rate, respiratory sinus arrhythmia, pre-ejection period, and cortisol measured during periods of rest and reactivity throughout a developmentally challenging protocol. Three distinct profiles of multisystem regulation emerged: heightened multisystem baseline activity (Anticipatory Arousal/ANS Responder), typically adaptive patterns across all systems (Active Copers/Mobilizers) and heightened HPA axis activity (HPA Axis Responders). Path models revealed that children exposed to adversity before 18-months were more likely to evidence an Anticipatory Arousal/ANS Responders response at 36-months, and children in this profile had lower executive functioning scores than the Active Copers/Mobilizers. In sum, these findings provide important information about potential physiological associations linking early adversity to variations in children's task-based executive functioning.

Countering the classical renin-angiotensin system

It is well-established that Ang-(1-7) counteracts the effects of Ang II in the periphery, while stimulating vasopressin release and mimicking the activity of Ang II in the brain, through interactions with various receptors. The rapid metabolic inactivation of Ang-(1-7) has proven to be a limitation to therapeutic administration of the peptide. To circumvent this problem, Alves et al. (Clinical Science (2021) 135(18), https://doi.org/10.1042/CS20210599) developed a new transgenic rat model that overexpresses an Ang-(1-7)-producing fusion protein. In this commentary, we discuss potential concerns with this model while also highlighting advances that can ensue from this significant technical feat.

Renal denervation as a management strategy for hypertension: current evidence and recommendations

INTRODUCTION

The concept of targeting the renal sympathetic nerves therapeutically to lower blood pressure (BP) is based on their crucial role in regulating both renal and cardiovascular control. These effects are mainly mediated via three major mechanisms including alteration of renal blood flow, renin-release, and Na⁺ retention. Initial surgical approaches applying crude and unselected sympathectomy, while rendering significant BP lowering and cardiovascular event reducing properties, where plagued by side effects. More modern selective catheter-based denervation approaches selectively targeting the renal nerves have been shown to be safe and effective in reducing BP in various forms of hypertension and multiple comorbidities.

AREAS COVERED

This article covers the background relevant for the concept of renal denervation (RDN), the evidence obtained from relevant randomized controlled trials to substantiate the safety and efficacy of RDN, and recently published clinical recommendations.

EXPERT OPINION

Catheter-based RDN is safe and has now been shown in sham-controlled randomized clinical trials to result in clinically meaningful BP lowering in both drug naïve hypertensive patients and those on concomitant antihypertensive therapy. Real world data from a large global registry further supports the clinical utility of RDN. It now seems time to embed renal denervation into routine clinical care.

Central catecholaminergic blockade with clonidine prevent SARS-CoV-2 complication: A case series

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SAR-CoV-2 infection lead to sympathetic overactivity.

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People with co morbid condition due to pre-sympathetic overactivity, there will be always possible of worse outcome.

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FDA-approved drug clonidine reduces sympathetic activity during COVID-19 infection and prevent complication and death.

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Clonidine should be considered early in incremental fashion to mitigate SAR-CoV-2 related complication.

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This is the first case series demonstrating the effectiveness of early use of clonidine in COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a life-threating viral infection that is highly transmissible and be lethal. Although many patients with mild symptoms recover, an acute form of the infection is characterized by rapidly evolving respiratory failure, an acute inflammatory response, organ failure, and death. Herein, we describe the use of clonidine to modulate the acute inflammatory consequences of this infection in three cases. The patients were three men between 40–50 years from Kathmandu valley, during the peak of COVID-19 (September 2020- January 2021). All three patients presented with typical COVID-19 symptoms (daily fever, loss of smell and taste, excessive fatigue, cough) and had pneumonia with typical finding in CT Scan of chest. Patient 1was able to maintain adequate oxygenation despite having pneumonia, managed at home by regular self-monitoring of vitals and treatment with oral clonidine whereas patient 2 and 3 developed significant pneumonia and had difficult in maintaining oxygenation hence admitted in hospital and treated with clonidine and supplemental oxygen. All three patients recovered completely. In this limited report, we proposed several mechanisms by which clonidine may be useful in managing rapidly evolving SARS-CoV-2 infection based on the rationale that early clonidine administration can intervene in the catecholaminergic response that characterizes rapid clinical deterioration including presumptive cytokine storm that occurs in COVID-19 infection in vulnerable populations.

Alpha- and beta- adrenergic receptors regulate inflammatory responses to acute and chronic sleep fragmentation in mice

Sleep is a recuperative process, and its dysregulation has cognitive, metabolic, and immunological effects that are largely deleterious to human health. Epidemiological and empirical studies have suggested that sleep fragmentation (SF) as result of obstructive sleep apnea (OSA) and other sleep abnormalities leads to pronounced inflammatory responses, which are influenced by the sympathetic nervous system (SNS). However, the underlying molecular mechanisms contributing to SNS regulation of SF-induced inflammation are not fully understood. To assess the effects of the SNS upon inflammatory responses to SF, C57BL/6j female mice were placed in automated SF chambers with horizontally moving bars across the bottom of each cage at specified intervals to disrupt sleep. Mice were first subjected to either control (no bar movement), acute sleep fragmentation (ASF), or chronic sleep fragmentation (CSF) on a 12:12-h light/dark schedule. ASF involved a bar sweep every 120 s for 24 h, whereas CSF involved a bar sweep every 120 s for 12 h (during 12 L; resting period) over a period of 4 weeks. After exposure to these conditions, mice received an intraperitoneal injection of either phentolamine (5 mg/kg BW; an α-adrenergic receptor blocker), propranolol (5 mg/kg BW; a β-adrenergic receptor blocker), or vehicle (saline). Serum corticosterone concentration, brain and peripheral cytokine (IL1β, TNFα, and TGFβ) mRNA expression, and body mass were assessed. ASF and CSF significantly elevated serum corticosterone concentrations as well as cytokine mRNA expression levels compared with controls, and mice subjected to CSF had decreased body mass relative to controls. Mice subjected to CSF and treated with phentolamine or propranolol had a greater propensity for a decrease in cytokine gene expression compared with ASF, but effects were tissue-specific. Taken together, these results suggest that both α- and β-adrenergic receptors contribute to the SNS mediation of inflammatory responses, and adrenergic antagonists may effectively mitigate tissue-specific SF-mediated inflammation.

Does transcutaneous electrical nerve stimulation affect pain, neuropathic pain, and sympathetic skin responses in the treatment of chronic low back pain? A randomized, placebo-controlled study

Background

The purpose of this study was to assess the effectiveness of transcutaneous electrical nerve stimulation (TENS) in chronic low back pain and neuropathic pain.

Methods

Seventy-four patients aged 18-65 with chronic low back pain were included in the study. Baseline measurements were performed, and patients were randomized into three groups. The first group received burst TENS (bTENS), the second group conventional TENS (cTENS), and the third group placebo TENS (pTENS), all over 15 sessions. Patients' visual analogue scale (VAS) scores were evaluated before treatment (preT), immediately after treatment (postT), and in the third month after treatment (postT3). Douleur Neuropathique 4 Questions (DN4), the Modified Oswestry Low Back Pain Disability Questionnaire (MOS), the Beck Depression Inventory (BDI), and sympathetic skin response (SSR) values were also evaluated preT and postT3.

Results

A statistically significant improvement was observed in mean VAS scores postT compared to preT in all three groups. Intergroup comparison revealed a significant difference between preT and postT values, that difference being assessed in favor of bTENS at multiple comparison analysis. Although significant improvement was determined in neuropathic pain DN4 scores measured at postT3 compared to preT in all groups, there was no significant difference between the groups. No statistically significant difference was also observed between the groups in terms of MOS, BDI, or SSR values at postT3 (P > 0.05).

Conclusions

bTENS therapy in patients with low back pain is an effective and safe method that can be employed in short-term pain control.

Nocturnal blood pressure is associated with sympathetic nerve activity in patients with chronic kidney disease

Elevated nocturnal blood pressure (BP) and nocturnal non-dipping are frequently observed in patients with chronic kidney disease (CKD) and are stronger predictors of cardiovascular complications and CKD progression than standard office BP. The sympathetic nervous system (SNS) is thought to modulate diurnal hemodynamic changes and the vascular endothelium plays a fundamental role in BP regulation. We hypothesized that SNS overactivity and endothelial dysfunction in CKD are linked to elevated nocturnal BP and non-dipping. In 32 CKD patients with hypertension (56 ± 7 years), office BP, 24-hr ambulatory BP, muscle sympathetic nerve activity (MSNA) and endothelial function via flow-mediated dilation (FMD) were measured. Participants were subsequently divided into dippers (nighttime average BP > 10% lower than the daytime average BP, n = 8) and non-dippers (n = 24). Non-dippers had higher nighttime BP (p < .05), but not office and daytime BP, compared to dippers. MSNA burst incidence (81 ± 13 versus 67 ± 13 bursts/100 HR, p = .019) was higher and brachial artery FMD (1.7 ± 1.5 versus 4.7 ± 1.9%, p < .001) was lower in non-dippers compared to dippers. MSNA and FMD each predicted nighttime systolic (β = 0.48,-0.46, p = .02, 0.07, respectively) and diastolic BP (β = 0.38,-0.47, p = .04, 0.03, respectively) in multivariate-adjusted analyses. Our novel findings demonstrate that unfavorable nocturnal BP profiles are associated with elevated SNS activity and endothelial dysfunction in CKD. Specifically, CKD patients with higher nighttime BP and the non-dipping pattern have higher MSNA and lower FMD. These support our hypothesis that SNS overactivation and endothelial dysfunction are linked to the dysregulation of nighttime BP as well as the magnitude of BP lowering at nighttime in CKD.

Neurocardiac regulation: from cardiac mechanisms to novel therapeutic approaches

Cardiac sympathetic overactivity is a well-established contributor to the progression of neurogenic hypertension and heart failure, yet the underlying pathophysiology remains unclear. Recent studies have highlighted the importance of acutely regulated cyclic nucleotides and their effectors in the control of intracellular calcium and exocytosis. Emerging evidence now suggests that a significant component of sympathetic overactivity and enhanced transmission may arise from impaired cyclic nucleotide signalling, resulting from compromised phosphodiesterase activity, as well as alterations in receptor-coupled G-protein activation. In this review, we address some of the key cellular and molecular pathways that contribute to sympathetic overactivity in hypertension and discuss their potential for therapeutic targeting.

Norepinephrine Has Dual Effects on Human Colonic Contractions Through Distinct Subtypes of Alpha 1 Adrenoceptors

BACKGROUND & AIMS

Colonic musculature contain smooth muscle cells (SMC), interstitial cells of Cajal (ICC), and platelet-derived growth factor receptor α+ cells (PDGFRα+ cells), which are electrically coupled and operate together as the SIP syncytium. PDGFRα+ cells have enriched expression of small conductance Ca2+-activated K+ (SK) channels. Purinergic enteric neural input activates SK channels in PDGFRα+ cells, hyperpolarizes SMC, and inhibits colonic contractions. Recently we discovered that PDGFRα+ cells in mouse colon have enriched expression of α1A adrenoceptors (ARs), which coupled to activation of SK channels and inhibited colonic motility, and α1A ARs were principal targets for sympathetic regulation of colonic motility. Here we investigated whether PDGFRα+ cells in human colon express α1A ARs and share the roles as targets for sympathetic regulation of colonic motility.

METHODS

Isometric tension recording, intracellular recording, and Ca2+ imaging were performed on muscles of the human colon. Responses to α1 ARs agonists or electric field stimulation with AR antagonists and neuroleptic reagents were studied.

RESULTS

Exogenous or endogenous norepinephrine released from nerve fibers inhibited colonic contractions through binding to α1A ARs or enhanced colonic contractions by acting on α1D ARs. Inhibitory responses were blocked by apamin, an antagonist of SK channels. Phenylephrine, α1 AR agonists, or norepinephrine increased intracellular [Ca2+] in PDGFRα+ cells, but not in ICC, and hyperpolarized SMCs by binding to α1 ARs expressed by PDGFRα+ cells.

CONCLUSIONS

Human colonic contractions are inhibited by α1A ARs expressed in PDGFRα+ cells and activated by α1D ARs expressed in SMC.

Effects of Alfuzosin, an α1-Adrenergic Antagonist, on Anal Pressures and Bowel Habits in Women With and Without Defecatory Disorders

BACKGROUND & AIMS

Some patients with defecatory disorders (DD) have high anal pressures that may impede rectal evacuation. Alpha-1 adrenoreceptors mediate as much as 50% of anal resting pressure in humans. We performed a randomized, placebo-controlled study of the effects of alfuzosin, an alpha1-adrenergic receptor antagonist, on anal pressures alone in healthy women and also on bowel symptoms in women with DD.

METHODS

In a double-blind study performed from March 2013 through March 2017, anal pressures were evaluated before and after 36 women with DD (constipation for at least 1 year) and 36 healthy women (controls) were randomly assigned (1:1) to groups given oral alfuzosin (2.5 mg immediate release) or placebo. Thereafter, patients were randomly assigned (1:1) to groups given oral alfuzosin (10 mg extended release) or placebo each day for 2 weeks. Participants kept daily diaries of bowel symptoms for 2 weeks before (baseline) and during administration of the test articles (treatment). Weekly questionnaires recorded the overall severity of constipation symptoms, bloating, abdominal pain, nausea, and vomiting; overall satisfaction with treatment of constipation was evaluated at weeks 2 and 4. The primary endpoint was the change in the number of spontaneous (SBMs) and complete SBMs (CSBMs) between the treatment and baseline periods. We evaluated relationships between stool form, passage, and complete evacuation.

RESULTS

Alfuzosin reduced anal resting pressure by 32 ± 3 mm Hg versus 16 ± 3 mm Hg for placebo (P = .0001) and anal pressure during evacuation by 26 ± 3 mm Hg versus 16 ± 3 mm Hg for placebo, (P = .03). However, alfuzosin did not significantly increase the rectoanal gradient, SBMs or CSBMs compared with placebo. Both formulations of alfuzosin were well tolerated. Hard stools and the ease of passage during defecation accounted for 72% and 76% of the variance in the satisfaction after defecation, respectively, during baseline and treatment periods.

CONCLUSIONS

In a randomized trial, alfuzosin reduced anal pressure at rest and during simulated evacuation in healthy and constipated women, compared with placebo, but did not improve bowel symptoms in constipated women. This could be because the drug does not improve stool form or dyssynergia, which also contribute to DD. ClinicalTrials.gov number, NCT 01834729.

Cardiovascular Responses of Women with Fibromyalgia to a Laboratory Stressor: Does Post-traumatic Stress Disorder Comorbidity Matter?

OBJECTIVES

This study compared cardiovascular responses to a laboratory trauma-unrelated stressor of two groups of women diagnosed with fibromyalgia (FM), one of them with comorbid post-traumatic stress disorder (PTSD), with a group of healthy controls in order to detect the possible existence of differences linked to comorbidity.

DESIGN

Case-controls.

METHODS

Eighteen women diagnosed with FM and comorbid PTSD, 18 women diagnosed with FM and no PTSD, and 38 healthy women were exposed to an arithmetic task with harassment while blood pressure and heart rate were measured during task exposure and recovery.

RESULTS

Although heart rate response evidenced a general blunted reactivity for both groups of FM patients, only those with comorbid PTSD presented lower levels of reactivity in terms of their systolic blood pressure response. In addition, systolic blood pressure response was sensitive to the presence of depression in both groups of FM patients and controls. Finally, although both groups of FM patients showed significantly slower rates of recovery, their final recovery state was not worse after twelve minutes of recording.

CONCLUSIONS

Results of this study point to comorbid PTSD as a significant contributor to the blunted cardiovascular reactivity observed in FM patients, which may be dependent to a great extent on depressive symptomatology. As some degree of cardiovascular response to stress is functional in that it mobilizes energy and triggers the necessary compensatory mechanisms to manage stressors, this study supports the well-recognized clinical strategies of detection and treatment of PTSD and concomitant depression in the management of FM.

A Longitudinal Observational Clinical Study of Neurophysiological and Patient-Reported Responses to a Program of Physiotherapy for Acute and Subacute Low Back Pain

OBJECTIVES

The purpose of this study was to document the baseline neurophysiological status (skin conductance activity levels) of patients presenting for physiotherapy with acute and subacute low back pain (symptoms of up to 12 weeks' duration) and to observe the magnitude and direction of sympathetic nervous system (SNS) changes (skin conductance responses [SCRs]) occurring as a result of receiving guideline-endorsed physiotherapy treatment.

METHODS

A pragmatic, prospective, longitudinal, observational study recording SNS skin conductance (SC) responses and patient reported outcome measure changes to a program of guideline-endorsed physiotherapy treatment for low back pain symptoms of up to 12 weeks' duration. Sixty patients received a guideline-endorsed physiotherapy treatment program. Continuous neurophysiological recordings of SC activity levels were taken throughout each treatment. Patient reported outcome measure data were extracted from inception, midpoint, and discharge. Within and between treatment analyses determined the nature of SC changes and correlations to longitudinal changes in pain and function. Skin conductance changes were measured within and between treatment episodes at treatment inception, midpoint, and discharge and observed correlations between the magnitude of SCRs, pain abatement (numeric pain rating scale), and functional restoration (Oswestry Disability Index).

RESULTS

Skin conductance changes were significant during all "treatment" periods (P = .044), with the greatest magnitude of sympathoexcitatory responses occurring at inception (219%). The treatment modality providing the maximum SNS response was a high-velocity lumbar rotation manipulation. Positive correlations were identified between SCRs, Oswestry Disability Index improvements (r = 0.82, P < .0005), and pain abatement (r = 0.459, P < .0005).

CONCLUSIONS

Patients with low back pain exhibited neurophysiological treatment responses indicative of a symptom-related neuroplastic state of dorsal horn sensitization that may be receptive to early manual therapy intervention.

Gender Differences in Heart Rate Variability Among Individuals Undergoing Regular Resistance Training Preliminary observations

OBJECTIVES

Frequency-domain analysis of heart rate variability (HRV) is an effective tool to evaluate autonomic balance. This study aimed to investigate gender differences in HRV among individuals undergoing regular resistance training.

METHODS

This preliminary cross-sectional study was conducted from April to September 2016 in João Pessoa, Paraíba, Brazil. The low-frequency (LF), high-frequency (HF) and LF/HF ratio components of HRV spectral analysis were analysed among 22 men and 27 women undergoing regular resistance training.

RESULTS

Among the male participants, the LF component was significantly increased compared to females in both the supine (1,171 ± 192 versus 545 ± 74 ms²; P = 0.0067) and upright (1,824 ± 260 versus 738 ± 133; P = 0.0011) positions. The LF/HF ratio was also significantly increased in both positions among male participants (P <0.0500 each).

CONCLUSION

These preliminary data suggest a possible gender difference in the HRV of individuals undergoing resistance training.

[Blood pressure rhythmicity in patients with end stage chronic kidney disease: bromocriptine effect]

BACKGROUND

The aim of this paper was to characterize the blood pressure CR in patients with end stage chronic kidney disease (ESCKD) before and after treatment with bromocriptine compared to healthy volunteers.

METHODS

Fifteen patients and nine healthy volunteers were included. Both groups underwent ambulatory 24 hours blood pressure (24 h ABPM). Patients received 2.5 mg every 8 hours of bromocriptine for eight weeks, at the end of the treatment 24 h ABPM was repeated; blood pressure CR was compared before and after treatment and with healthy volunteers. The CR was identified by the method of Cosinor.

RESULTS

64% of volunteers showed a 24 h CR, against 27% of patients (p < 0.05). After the treatment with bromocriptine 40% of patients showed RC 24 h. The mean arterial pressure decreased from 129 ± 1 mmHg to 106 ± 1 mmHg. A 12 h rhythm was identified in 45% of volunteers and 73% of patients before treatment (p < 0.05) against 60% at the end (p < 0.001), with no statistical difference with volunteers.

CONCLUSIONS

The CR in blood pressure is altered in ESCKD and could be restored with bromocriptine. 12 hours rhythmicity was identified predominantly in patients with ESCKD; this rhythm was also present in the healthy volunteers.

Therapeutic potential of stellate ganglion block in orofacial pain: a mini review

Orofacial pain is a common complaint of patients that causes distress and compromises the quality of life. It has many etiologies including trauma, interventional procedures, nerve injury, varicella-zoster (shingles), tumor, and vascular and idiopathic factors. It has been demonstrated that the sympathetic nervous system is usually involved in various orofacial pain disorders such as postherpetic neuralgia, complex regional pain syndromes, and atypical facial pain. The stellate sympathetic ganglion innervates the head, neck, and upper extremity. In this review article, the effect of stellate ganglion block and its mechanism of action in orofacial pain disorders are discussed.

Alpha-Blocker Treatment Response in Men With Lower Urinary Tract Symptoms Based on Sympathetic Activity: Prospective, Multicenter, Open-Labeled, Observational Study

Purpose:

In this study, we compared the treatment outcomes for an α-blocker between 2 groups of men, one with high sympathetic activity (HSA) and another with low sympathetic activity (LSA) or normal sympathetic activity.

Methods:

A total of 159 men (≥50 years of age) with lower urinary tract symptoms resulting from benign prostatic hyperplasia were analyzed. We assigned patients to groups according to their sympathetic activity, which was evaluated by heart ratevariability measurements. HSA was defined as a low frequency/high frequency ratio greater than 1.6. All patients received 10mg of alfuzosin once a day for 12 weeks. The primary end point was a change in the total International Prostate SymptomScore (IPSS) at 12 weeks from baseline.

Results:

Sixty-seven men were assigned to the HSA group and 92 men were assigned to the LSA group. The baseline characteristics were not significantly different between the 2 groups, and the response to alfuzosin was good in both groups. Themean total IPSS change was not different between the groups. Both groups were not significantly different with respect to the changes in maximal flow rate, IPSS voiding or storage symptom subscores, quality of life, and rates of adverse drug events. TheHSA group showed a similar willingness to continue treatment compared to the LSA group, although their treatment satisfaction rating was lower.

Conclusions:

The therapeutic effects of alfuzosin did not differ in regards to the differences in sympathetic activity, but treatment satisfaction ratings were lower in the HSA group.

Extracellular norepinephrine clearance by the norepinephrine transporter is required for skeletal homeostasis

Changes in bone remodeling induced by pharmacological and genetic manipulation of β-adrenergic receptor (βAR) signaling in osteoblasts support a role of sympathetic nerves in the regulation of bone remodeling. However, the contribution of endogenous sympathetic outflow and nerve-derived norepinephrine (NE) to bone remodeling under pathophysiological conditions remains unclear. We show here that differentiated osteoblasts, like neurons, express the norepinephrine transporter (NET), exhibit specific NE uptake activity via NET and can catabolize, but not generate, NE. Pharmacological blockade of NE transport by reboxetine induced bone loss in WT mice. Similarly, lack of NE reuptake in norepinephrine transporter (Net)-deficient mice led to reduced bone formation and increased bone resorption, resulting in suboptimal peak bone mass and mechanical properties associated with low sympathetic outflow and high plasma NE levels. Last, daily sympathetic activation induced by mild chronic stress was unable to induce bone loss, unless NET activity was blocked. These findings indicate that the control of endogenous NE release and reuptake by presynaptic neurons and osteoblasts is an important component of the complex homeostatic machinery by which the sympathetic nervous system controls bone remodeling. These findings also suggest that drugs antagonizing NET activity, used for the treatment of hyperactivity disorders, may have deleterious effects on bone accrual.

Peptidergic regulation of plasminogen activator inhibitor-1 gene expression in vivo

BACKGROUND

The mechanisms by which PAI-1 biosynthesis is altered during stress have not been fully elucidated. Studies suggest a major role for neuro-peptidergic modulation of the stress response by PACAP (pituitary adenylate cyclase-activating polypeptide), a member of the VIP/secretin/glucagon family.

OBJECTIVE

We tested the hypothesis that PACAP regulates PAI-1 biosynthesis during stress in vivo.

METHODS

PAI-1 gene expression was monitored by RT-PCR in adrenal glands harvested from C57BL/6J mice that were unstressed, or subjected to restraint stress for 2 h, or treated with PACAP.

RESULTS

PAI-1 mRNA expression was markedly increased in adrenals from stressed mice. Restraint stress resulted in much smaller increments in adrenal tPA mRNA, suggesting that local adrenal tPA/PAI-1 biosynthetic balance is markedly altered by stress. The observed increases in PAI-1mRNA during stress were substantially blunted (55 ± 4%, P < 0.001) by pretreatment with the specific PACAP receptor antagonist, PACAP6-38, compared with pretreatment with vehicle. Administration of the agonist PACAP1-38 alone resulted in a dose-dependent increase in tissue PAI-1 mRNA. PACAP1-38 administration also resulted in substantial increases in plasma PAI-1 antigen and active PAI-1 concentrations that were significantly greater in male mice than in female mice.

CONCLUSIONS

We conclude that adrenal PAI-1 mRNA expression is markedly increased by stress, and that the PACAP peptidergic signaling pathway plays a major role in mediating the stress-induced increase in PAI-1 biosynthesis.

Acupuncture's Cardiovascular Actions: A Mechanistic Perspective

Over the last several decades, there has been an explosion of articles on acupuncture, including studies that have begun to explore mechanisms underlying its analgesic and cardiovascular actions. Modulation of cardiovascular function is most effective during manual and low-frequency, low-intensity electroacupuncture (EA) at a select set of acupoints situated along meridians located over deep somatic nerves on the upper and lower extremities. Stimulation at these acupoints activates underlying sensory neural pathways that project to a number of regions in the central nervous system (CNS) that ultimately regulate autonomic outflow and hence cardiovascular function. A long-loop pathway involving the hypothalamus, midbrain, and medulla underlies EA modulation of reflex increases in blood pressure (BP). Actions of excitatory and inhibitory neurotransmitters in the supraspinal CNS underlie processing of the somatic input and adjustment of autonomic outflow during EA. Acupuncture also decreases elevated blood pressure through actions in the thoracic spinal cord. Reflexes that lower BP likewise are modulated by EA through its actions on sympathetic and parasympathetic nuclei in the medulla. The autonomic influence of acupuncture is slow in onset but prolonged in duration, typically lasting beyond the period of stimulation. Clinical studies suggest that acupuncture can be used to treat cardiac diseases, such as myocardial ischemia and hypertension, associated with overactivity of the sympathetic nervous system.

Strain differences in baroceptor reflex in adult Wistar Kyoto rats

OBJECTIVES

A subset of normotensive Sprague-Dawley rats show lower baroreflex sensitivity; however, no previous study investigated whether there are differences in baroreflex sensitivity within this subset. Our study compared baroreflex sensitivity among conscious rats of this specific subtype.

METHODS

Male Wistar Kyoto (WKY) rats (16 weeks old) were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure (MAP) and heart rate (HR). Baroreflex gain was calculated as the ratio between change in HR and MAP variation (DeltaHR/DeltaMAP) in response to a depressor dose of sodium nitroprusside (SNP, 50 microg/kg, i.v.) and a pressor dose of phenylephrine (PE, 8 microg/kg, i.v.). Rats were divided into four groups: 1) low bradycardic baroreflex (LB), baroreflex gain (BG) between -1 and -2 bpm/mmHg tested with PE; 2) high bradycardic baroreflex (HB), BG < -2 bpm/mmHg tested with PE; 3) low tachycardic baroreflex (LT), BG between -1 and -2 bpm/mmHg tested with SNP and; 4) high tachycardic baroreflex (HT), BG < -2 bpm/mmHg tested with SNP. Significant differences were considered for p < 0.05.

RESULTS

Approximately 37% of the rats showed a reduced bradycardic peak, bradycardic reflex and decreased bradycardic gain of baroreflex while roughly 23% had a decreased basal HR, tachycardic peak, tachycardic reflex and reduced sympathetic baroreflex gain. No significant alterations were noted with regard to basal MAP.

CONCLUSION

There is variability regarding baroreflex sensitivity among WKY rats from the same laboratory.