Psychoneuroimmunologic effects of Ayurvedic oil-dripping treatment.

PubMed

Uebaba, Kazuo; Xu, Feng-Hao; Ogawa, Hiroko; Tatsuse, Takashi; Wang, Bing-Hong; Hisajima, Tatsuya; Venkatraman, Sonia

2008-12-01

This study assessed the psychoneuroimmunologic changes achieved by Shirodhara, an Ayurvedic treatment, characterized by dripping oil on the forehead, in a randomized, controlled protocol involving a novel approach using a robotic system. In the first experiment for the determination of the most appropriate conditions of Shirodhara, 16 healthy females (33 +/- 9 years old) underwent a 30-minute treatment. In the second study, another 16 healthy females (39 +/- 9 years old) were assigned to either the Shirodhara treatment or control supine position for 30 minutes, with monitoring of physiologic, biochemical, immunologic, and psychometric parameters including anxiety and altered states of consciousness (ASC). The subjects receiving Shirodhara treatment showed lowered levels of state anxiety and higher levels of ASC than those in the control position. Plasma noradrenaline and urinary serotonin excretion decreased significantly more after Shirodhara treatment than in the control. Plasma levels of thyrotropin-releasing hormone, dopamine, and natural killer (NK) cell activity were different between control and Shirodhara treatment. The correlation between anxiolysis and the depth of ASC was significant in the Shirodhara treatment group (r = 0.52, p < 0.05, N = 16), while in the control no correlation was obtained (r = 0.13, p = 0.64, N = 16). The increase in foot skin temperature after Shirodhara showed a significant correlation with anxiolysis and the depth of Trance of ASC (r = 0.58, p < 0.01, r = 0.43, p < 0.01, respectively). NK cell activity after Shirodhara treatment showed a significant correlation with anxiolysis and the depth of Trance of ASC (r = 0.33, p < 0.05, r = 0.56, p < 0.01, respectively). These results indicate that Shirodhara has anxiolytic and ASC-inducing effects, and it promotes a decrease of noradrenaline and exhibits a sympatholytic effect, resulting in the activation of peripheral foot skin circulation and immunopotentiation.

Timed Bromocriptine-QR Therapy Reduces Progression of Cardiovascular Disease and Dysglycemia in Subjects with Well-Controlled Type 2 Diabetes Mellitus

PubMed Central

Chamarthi, Bindu; Gaziano, J. Michael; Blonde, Lawrence; Scranton, Richard E.; Ezrokhi, Michael; Rutty, Dean; Cincotta, Anthony H.

2015-01-01

Background. Type 2 diabetes (T2DM) patients, including those in good glycemic control, have an increased risk of cardiovascular disease (CVD). Maintaining good glycemic control may reduce long-term CVD risk. However, other risk factors such as elevated vascular sympathetic tone and/or endothelial dysfunction may be stronger potentiators of CVD. This study evaluated the impact of bromocriptine-QR, a sympatholytic dopamine D2 receptor agonist, on progression of metabolic disease and CVD in T2DM subjects in good glycemic control (HbA1c ≤7.0%). Methods. 1834 subjects (1219 bromocriptine-QR; 615 placebo) with baseline HbA1c ≤7.0% derived from the Cycloset Safety Trial (this trial is registered with ClinicalTrials.gov Identifier: NCT00377676), a 12-month, randomized, multicenter, placebo-controlled, double-blind study in T2DM, were evaluated. Treatment impact upon a prespecified composite CVD endpoint (first myocardial infarction, stroke, coronary revascularization, or hospitalization for angina/congestive heart failure) and the odds of losing glycemic control (HbA1c >7.0% after 52 weeks of therapy) were determined. Results. Bromocriptine-QR reduced the CVD endpoint by 48% (intention-to-treat; HR: 0.52 [0.28−0.98]) and 52% (on-treatment analysis; HR: 0.48 [0.24−0.95]). Bromocriptine-QR also reduced the odds of both losing glycemic control (OR: 0.63 (0.47−0.85), p = 0.002) and requiring treatment intensification to maintain HbA1c ≤7.0% (OR: 0.46 (0.31−0.69), p = 0.0002). Conclusions. Bromocriptine-QR therapy slowed the progression of CVD and metabolic disease in T2DM subjects in good glycemic control. PMID:26060823

Dual autonomic inhibitory action of central Apelin on gastric motor functions in rats.

PubMed

Bülbül, Mehmet; Sinen, Osman

2018-07-01

Centrally administered apelin has been shown to inhibit gastric emptying (GE) in rodents, however, the relevant mechanism has been investigated incompletely. Using male Wistar rats, we investigated the efferent pathways involved in gastroinhibitory action of central apelin. Stereotaxic intracerebroventricular (icv) cannulation, subdiaphragmatic vagotomy (VGX) and/or celiac ganglionectomy (CGX) were performed 7 days prior to the experiments. Apelin-13 was administered (30 nmol, icv) 90 min prior to GE measurement. Nitric oxide synthase inhibitor L-NAME (100 mg/kg), sympatholytic agent guanethidine (5 mg/kg) and/or muscarinic receptor agonist bethanechol (1 mg/kg) were administered intraperitoneally 30 min prior to the central apelin-13 injection. Two strain gages were implanted serosally onto antrum and pylorus to monitor gastric postprandial motility. Heart rate variability (HRV) analysis was performed before and after central vehicle or apelin-13 administration. Apelin-13 delayed solid GE significantly by disturbing coordinated antral and pyloric postprandial contractions. The apelin-induced delayed GE was attenuated partially by CGX or VGX, whereas it was restored completely in rats underwent both CGX and VGX. L-NAME did not change the apelin-induced alterations. Guanethidine or bethanechol restored the apelin-induced gastroinhibition partially, while it was abolished completely in rats received both agents. Apelin-13 decreased the HRV spectral activity in high-frequency range by increasing low-frequency component and the ratio of LF:HF. The present data suggest that (1) both vagal parasympathetic and sympathetic pathways play a role in apelin-induced gastroinhibition, (2) central apelin attenuates vagal cholinergic pathway rather than activating nonadrenergic-noncholinergic pathway. Apelin/APJ receptor system might be candidate for the treatment of autonomic dysfunction and gastrointestinal motor disorders. Copyright © 2018 Elsevier B.V. All rights reserved.

Manipulation of norepinephrine metabolism with yohimbine in the treatment of autonomic failure

NASA Technical Reports Server (NTRS)

Biaggioni, I.; Robertson, R. M.; Robertson, D.

1994-01-01

It has been postulated that alpha 2-adrenergic receptors play a modulatory role in the regulation of blood pressure. Activation of alpha 2-receptors located in the central nervous system results in inhibition of sympathetic tone and decrease of blood pressure. This indeed may be the mechanism of action of central sympatholytic antihypertensives such as alpha-methyldopa. Presynaptic alpha 2-receptors also are found in adrenergic nerve terminals. These receptors act as a negative feedback mechanism by inhibiting the release of norepinephrine. The relevance of alpha 2-adrenergic receptors for blood pressure regulation can be explored with yohimbine, a selective antagonist of these receptors. Yohimbine increases blood pressure in resting normal volunteers. This effect is associated with an increase in both sympathetic nerve activity, reflecting an increase in central sympathetic outflow, and in norepinephrine spillover, reflecting potentiation of the release of norepinephrine from adrenergic nerve terminals. These actions, therefore, underscore the importance of alpha 2-adrenergic receptors for blood pressure regulation even under resting conditions. Patients with autonomic failure, even those with severe sympathetic deprivation, are hypersensitive to the pressor effects of yohimbine. This increased responsiveness can be explained by sensitization of adrenergic receptors, analogous to denervation supersensitivity, and by the lack of autonomic reflexes that would normally buffer any increase in blood pressure. Preliminary studies suggest that the effectiveness of yohimbine in autonomic failure can be enhanced with monoamine oxidase inhibitors. Used in combination, yohimbine increases norepinephrine release, whereas monoamine oxidase inhibitors inhibit its degradation. Therefore, yohimbine is not only a useful tool in the study of blood pressure regulation, but may offer a therapeutic option in autonomic dysfunction.

[Indications and possibilities of blockade of the sympathetic nerve].

PubMed

Meyer, J

1987-04-01

Treatment of chronic pain through permanent or temporary interruption of sympathetic activity is marked by great clinical success, but nevertheless there are rather skeptical reports about long-term results of these blocks as therapeutic measures. There are many symptoms and signs of chronic pain, while diagnosis is expensive, the pathogenesis is complex, and the etiology is generally due to multiple factors. Indications for sympathetic blockade depend upon the possible means of access, as in the cervicothoracic, thoracic, lumbar, or sacral regions. General indications are: symptoms not limited segmentally within peripheral body areas; pain resulting from microtraumata and lesions of peripheral nerve branches; and pain caused by intensified sympathetic tone with consequent circulatory disturbances. Peripheral circulatory disturbances are the most common indication for sympathetic blockade, as the block produces a vasomotor reaction that leads to increased capillary circulation. Pain caused by herpes zoster, sudden hearing loss, hyperhidrosis, and pseudesthesia can also be influenced by sympathetic blockade. There are several possibilities for reducing or interrupting sympathetic activity; for us, however, blocking of the sympathetic trunk is the most important. During the last 16 years we performed 15,726 sympathetic blockades on 2385 patients, which included: 3735 stellate ganglion blocks, 6121 blocks of the lumbar sympathetic trunk, 5037 continuous peridural anesthesias, 29 blocks of the thoracic sympathetic trunk, and 12 celiac blocks. In 792 cases sympathetic blocks were performed using neurolytic drugs, in most cases 96% ethyl alcohol and less often 10% ammonium sulphate. Other possibilities, such as enteral administration or infusion of sympatholytic drugs, were not taken into consideration; regional intravascular injection of guanethidine can be recommended, however.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of renal sympathetic denervation on cardiac sympathetic activity and function in patients with therapy resistant hypertension.

PubMed

van Brussel, Peter M; Eeftinck Schattenkerk, Daan W; Dobrowolski, Linn C; de Winter, Robbert J; Reekers, Jim A; Verberne, Hein J; Vogt, Liffert; van den Born, Bert-Jan H

2016-01-01

Renal sympathetic denervation (RSD) is currently being investigated in multiple studies of sympathetically driven cardiovascular diseases such as heart failure and arrhythmias. Our aim was to assess systemic and cardiac sympatholytic effects of RSD by the measurement of cardiac sympathetic activity and cardiovascular parameters. A total of 21 consecutive patients with refractory hypertension (daytime ambulatory blood pressure (BP)≥150/100 mmHg despite the use of 3 or more antihypertensive drugs), no evidence for secondary hypertension and normal renovascular anatomy were included. RSD was performed with the Medtronic Symplicity renal denervation catheter with an average of 4.2 (range 3-6) ablations per renal artery. To assess cardiac sympathetic activity, 123I-mIBG cardiac scintigraphy was performed before and 6 weeks after. In addition, the effect of RSD on peripheral BP and cardiac hemodynamics were assessed non-invasively. 123I-mIBG uptake before and after RSD was 1.7±0.4% vs. 1.7±0.5% at 15 min. and 1.4±0.4% vs. 1.5±0.5% after 4 h. As a consequence, washout rate was similar before (33.7±11.7%) and after RSD (30.1±12.6%, p=0.27). In line with earlier RSD studies, a significant drop in systolic office BP (-12.2 mmHg, p=0.04) was detected, whereas the decrease in ambulatory BP was not significant. No changes were seen in heart rate, stroke volume or left ventricular contractility, both in supine position and after standing. In concert with previous reports, RSD leads to a significant drop in office BP. However, a reduction in sympathetic activity could not be demonstrated on a cardiac level. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

REFRACTORY HYPERTENSION: EVIDENCE OF HEIGHTENED SYMPATHETIC ACTIVITY AS A CAUSE OF ANTIHYPERTENSIVE TREATMENT FAILURE

PubMed Central

Dudenbostel, Tanja; Acelajado, Maria C.; Pisoni, Roberto; Li, Peng; Oparil, Suzanne; Calhoun, David A.

2015-01-01

Refractory hypertension is an extreme phenotype of treatment failure defined as uncontrolled blood pressure (BP) in spite of ≥5 classes of antihypertensive agents, including chlorthalidone and a mineralocorticoid receptor antagonist. A prospective evaluation of possible mechanisms of refractory hypertension has not been done. The goal of this study was to test for evidence of heightened sympathetic tone as indicated by 24-hr urinary (U-) normetanephrine levels, clinic and ambulatory heart rate (HR), HR variability (HRV), arterial stiffness as indexed by pulse wave velocity (PWV), and systemic vascular resistance (SVR) compared to patients with controlled resistant hypertension. Forty-four consecutive patients, 15 with refractory and 29 with controlled resistant hypertension, were evaluated prospectively. Refractory hypertensive patients were younger (48±13.3 vs. 56.5±14.1 years, p=0.038) and more likely female (80.0 vs 51.9 %, p=0.047) compared to patients with controlled resistant hypertension. They also had higher U-normetanephrine levels (464.4±250.2 vs. 309.8±147.6 μg/24h, p=0.03), higher clinic HR (77.8±7.7 vs. 68.8±7.6 bpm, p=0.001) and 24-hr ambulatory HR (77.8±7.7 vs 68.8±7.6, p=0.0018), higher PWV (11.8±2.2 vs. 9.4±1.5 m/s, p=0.009), reduced HRV (4.48 vs. 6.11, p=0.03), and higher SVR (3795±1753 vs. 2382±349 dyne·sec·cm5·m2, p=0.008). These findings are consistent with heightened sympathetic tone being a major contributor to antihypertensive treatment failure and highlight the need for effective sympatholytic therapies in patients with refractory hypertension. PMID:25987662

Exercise training modulates functional sympatholysis and α-adrenergic vasoconstrictor responsiveness in hypertensive and normotensive individuals

PubMed Central

Mortensen, Stefan P; Nyberg, Michael; Gliemann, Lasse; Thaning, Pia; Saltin, Bengt; Hellsten, Ylva

2014-01-01

Essential hypertension is linked to an increased sympathetic vasoconstrictor activity and reduced tissue perfusion. We investigated the role of exercise training on functional sympatholysis and postjunctional α-adrenergic responsiveness in individuals with essential hypertension. Leg haemodynamics were measured before and after 8 weeks of aerobic training (3–4 times per week) in eight hypertensive (47 ± 2 years) and eight normotensive untrained individuals (46 ± 1 years) during arterial tyramine infusion, arterial ATP infusion and/or one-legged knee extensions. Before training, exercise hyperaemia and leg vascular conductance (LVC) were lower in the hypertensive individuals (P < 0.05) and tyramine lowered exercise hyperaemia and LVC in both groups (P < 0.05). Training lowered blood pressure in the hypertensive individuals (P < 0.05) and exercise hyperaemia was similar to the normotensive individuals in the trained state. After training, tyramine did not reduce exercise hyperaemia or LVC in either group. When tyramine was infused at rest, the reduction in blood flow and LVC was similar between groups, but exercise training lowered the magnitude of the reduction in blood flow and LVC (P < 0.05). There was no difference in the vasodilatory response to infused ATP or in muscle P2Y2 receptor content between the groups before and after training. However, training lowered the vasodilatory response to ATP and increased skeletal muscle P2Y2 receptor content in both groups (P < 0.05). These results demonstrate that exercise training improves functional sympatholysis and reduces postjunctional α-adrenergic responsiveness in both normo- and hypertensive individuals. The ability for functional sympatholysis and the vasodilator and sympatholytic effect of intravascular ATP appear not to be altered in essential hypertension. PMID:24860173

Timed Bromocriptine-QR Therapy Reduces Progression of Cardiovascular Disease and Dysglycemia in Subjects with Well-Controlled Type 2 Diabetes Mellitus.

PubMed

Chamarthi, Bindu; Gaziano, J Michael; Blonde, Lawrence; Vinik, Aaron; Scranton, Richard E; Ezrokhi, Michael; Rutty, Dean; Cincotta, Anthony H

2015-01-01

Type 2 diabetes (T2DM) patients, including those in good glycemic control, have an increased risk of cardiovascular disease (CVD). Maintaining good glycemic control may reduce long-term CVD risk. However, other risk factors such as elevated vascular sympathetic tone and/or endothelial dysfunction may be stronger potentiators of CVD. This study evaluated the impact of bromocriptine-QR, a sympatholytic dopamine D2 receptor agonist, on progression of metabolic disease and CVD in T2DM subjects in good glycemic control (HbA1c ≤ 7.0%). 1834 subjects (1219 bromocriptine-QR; 615 placebo) with baseline HbA1c ≤ 7.0% derived from the Cycloset Safety Trial (this trial is registered with ClinicalTrials.gov Identifier: NCT00377676), a 12-month, randomized, multicenter, placebo-controlled, double-blind study in T2DM, were evaluated. Treatment impact upon a prespecified composite CVD endpoint (first myocardial infarction, stroke, coronary revascularization, or hospitalization for angina/congestive heart failure) and the odds of losing glycemic control (HbA1c >7.0% after 52 weeks of therapy) were determined. Bromocriptine-QR reduced the CVD endpoint by 48% (intention-to-treat; HR: 0.52 [0.28-0.98]) and 52% (on-treatment analysis; HR: 0.48 [0.24-0.95]). Bromocriptine-QR also reduced the odds of both losing glycemic control (OR: 0.63 (0.47-0.85), p = 0.002) and requiring treatment intensification to maintain HbA1c ≤ 7.0% (OR: 0.46 (0.31-0.69), p = 0.0002). Bromocriptine-QR therapy slowed the progression of CVD and metabolic disease in T2DM subjects in good glycemic control.

Dexmedetomidine for Refractory Adrenergic Crisis in Familial Dysautonomia

PubMed Central

Dillon, Ryan C.; Palma, Jose-Alberto; Spalink, Christy L.; Altshuler, Diana; Norcliffe-Kaufmann, Lucy; Fridman, David; Papadopoulos, John; Kaufmann, Horacio

2016-01-01

Objective Adrenergic crises are a cardinal feature of familial dysautonomia (FD). Traditionally, adrenergic crisis have been treated with the sympatholytic agent clonidine or with benzodiazepines, which can cause excessive sedation and respiratory depression. Dexmedetomidine is an α2A-adrenergic agonist with greater selectivity and shorter half-life than clonidine. We aimed to evaluate the preliminary effectiveness and safety of intravenous dexmedetomidine in the treatment of refractory adrenergic crisis in patients with FD. Methods Retrospective chart review of patients with genetically confirmed FD who received intravenous dexmedetomidine for refractory adrenergic crises. The primary outcome was preliminary effectiveness of dexmedetomidine defined as change in blood pressure (BP) and heart rate (HR) 1-hour after the initiation of dexmedetomidine. Secondary outcomes included incidence of adverse events related to dexmedetomidine, hospital and intensive care unit (ICU) length of stay, and hemodynamic parameters 12-hours after dexmedetomidine cessation. Results Nine patients over 14 admissions were included in the final analysis. At 1-hour after the initiation of dexmedetomidine, systolic BP decreased from 160±7 to 122±7 mmHg (p=0.0005), diastolic BP decreased from 103±6 to 65±8 (p=0.0003), and HR decreased from 112±4 to 100±5 bpm (p=0.0047). The median total adverse events during dexmedetomidine infusion was 1 per admission. Median hospital length of stay was 9 days (IQR, 3 – 11 days) and median ICU length of stay was 7 days (IQR, 3 – 11 days). Conclusions Intravenous dexmedetomidine is safe in patients with FD and appears to be effective to treat refractory adrenergic crisis. Dexmedetomidine may be considered in FD patients who do not respond to conventional clonidine and benzodiazepine pharmacotherapy. PMID:27752785

Elevated blood pressure, heart rate and body temperature in mice lacking the XLαs protein of the Gnas locus is due to increased sympathetic tone.

PubMed

Nunn, Nicolas; Feetham, Claire H; Martin, Jennifer; Barrett-Jolley, Richard; Plagge, Antonius

2013-10-01

Imbalances of energy homeostasis are often associated with cardiovascular complications. Previous work has shown that Gnasxl-deficient mice have a lean and hypermetabolic phenotype, with increased sympathetic stimulation of adipose tissue. The Gnasxl transcript from the imprinted Gnas locus encodes the trimeric G-protein subunit XLαs, which is expressed in brain regions that regulate energy homeostasis and sympathetic nervous system (SNS) activity. To determine whether Gnasxl knock-out (KO) mice display additional SNS-related phenotypes, we have now investigated the cardiovascular system. The Gnasxl KO mice were ∼20 mmHg hypertensive in comparison to wild-type (WT) littermates (P ≤ 0.05) and hypersensitive to the sympatholytic drug reserpine. Using telemetry, we detected an increased waking heart rate in conscious KOs (630 ± 10 versus 584 ± 12 beats min(-1), KO versus WT, P ≤ 0.05). Body temperature was also elevated (38.1 ± 0.3 versus 36.9 ± 0.4°C, KO versus WT, P ≤ 0.05). To investigate autonomic nervous system influences, we used heart rate variability analyses. We empirically defined frequency power bands using atropine and reserpine and verified high-frequency (HF) power and low-frequency (LF) LF/HF power ratio to be indicators of parasympathetic and sympathetic activity, respectively. The LF/HF power ratio was greater in KOs and more sensitive to reserpine than in WTs, consistent with elevated SNS activity. In contrast, atropine and exendin-4, a centrally acting agonist of the glucagon-like peptide-1 receptor, which influences cardiovascular physiology and metabolism, reduced HF power equally in both genotypes. This was associated with a greater increase in heart rate in KOs. Mild stress had a blunted effect on the LF/HF ratio in KOs consistent with elevated basal sympathetic activity. We conclude that XLαs is required for the inhibition of sympathetic outflow towards cardiovascular and metabolically relevant tissues.

Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis.

PubMed

Liao, Chun-De; Tsauo, Jau-Yih; Liou, Tsan-Hon; Chen, Hung-Chou; Rau, Chi-Lun

2016-01-01

Stellate ganglion blockade (SGB) is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs), such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated the use of noninvasive SGB for managing neuropathic pain or other disorders associated with sympathetic hyperactivity. We performed a comprehensive search of the following online databases: Medline, PubMed, Excerpta Medica Database, Cochrane Library Database, Ovid MEDLINE, Europe PubMed Central, EBSCOhost Research Databases, CINAHL, ProQuest Research Library, Physiotherapy Evidence Database, WorldWideScience, BIOSIS, and Google Scholar. We identified and included quasi-randomized or randomized controlled trials reporting the efficacy of SGB performed using therapeutic ultrasound, transcutaneous electrical nerve stimulation, light irradiation using low-level laser therapy, or xenon light or linearly polarized near-infrared light irradiation near or over the stellate ganglion region in treating complex regional pain syndrome or disorders requiring sympatholytic management. The included articles were subjected to a meta-analysis and risk of bias assessment. Nine randomized and four quasi-randomized controlled trials were included. Eleven trials had good methodological quality with a Physiotherapy Evidence Database (PEDro) score of ≥6, whereas the remaining two trials had a PEDro score of <6. The meta-analysis results revealed that the efficacy of noninvasive SGB on 100-mm visual analog pain score is higher than that of a placebo or active control (weighted mean difference, -21.59 mm; 95% CI, -34.25, -8.94; p = 0.0008). Noninvasive SGB performed using PAMs effectively relieves pain of various etiologies, making it a valuable addition to the contemporary pain management armamentarium. However, this evidence is limited by the potential risk of bias.

Stress-associated cardiovascular reaction masks heart rate dependence on physical load in mice.

PubMed

Andreev-Andrievskiy, A A; Popova, A S; Borovik, A S; Dolgov, O N; Tsvirkun, D V; Custaud, M; Vinogradova, O L

2014-06-10

When tested on the treadmill mice do not display a graded increase of heart rate (HR), but rather a sharp shift of cardiovascular indices to high levels at the onset of locomotion. We hypothesized that under test conditions cardiovascular reaction to physical load in mice is masked with stress-associated HR increase. To test this hypothesis we monitored mean arterial pressure (MAP) and heart rate in C57BL/6 mice after exposure to stressful stimuli, during spontaneous locomotion in the open-field test, treadmill running or running in a wheel installed in the home cage. Mice were treated with β1-adrenoblocker atenolol (2mg/kg ip, A), cholinolytic ipratropium bromide (2mg/kg ip, I), combination of blockers (A+I), anxiolytic diazepam (5mg/kg ip, D) or saline (control trials, SAL). MAP and HR in mice increased sharply after handling, despite 3weeks of habituation to the procedure. Under stressful conditions of open field test cardiovascular parameters in mice were elevated and did not depend on movement speed. HR values did not differ in I and SAL groups and were reduced with A or A+I. HR was lower at rest in D pretreated mice. In the treadmill test HR increase over speeds of 6, 12 and 18m/min was roughly 1/7-1/10 of HR increase observed after placing the mice on the treadmill. HR could not be increased with cholinolytic (I), but was reduced after sympatholytic (A) or A+I treatment. Anxiolytic (D) reduced heart rate at lower speeds of movement and its overall effect was to unmask the dependency of HR on running speed. During voluntary running in non-stressful conditions of the home cage HR in mice linearly increased with increasing running speeds. We conclude that in test situations cardiovascular reactions in mice are governed predominantly by stress-associated sympathetic activation, rendering efforts to evaluate HR and MAP reactions to workload unreliable. Copyright © 2014 Elsevier Inc. All rights reserved.

Actions of rilmenidine on neurogenic hypertension in BPH/2J genetically hypertensive mice.

PubMed

Jackson, Kristy L; Palma-Rigo, Kesia; Nguyen-Huu, Thu-Phuc; Davern, Pamela J; Head, Geoffrey A

2014-03-01

BPH/2J hypertensive mice have an exaggerated sympathetic contribution to blood pressure (BP). Premotor sympathetic neurons within the rostroventrolateral medulla (RVLM) are a major source of sympathetic vasomotor tone and major site of action of the centrally acting sympatholytic agent, rilmenidine. The relative cardiovascular effect of rilmenidine in BPH/2J versus normotensive BPN/3J mice was used as an indicator of the involvement of the RVLM in the sympathetic contribution to hypertension in BPH/2J mice. BPH/2J and BPN/3J mice were pre-implanted with telemetry devices to measure BP in conscious unrestrained mice. Rilmenidine was administered acutely (n=7-9/group), orally for 14 days, at a wide range of doses (n=5/group), and also infused intracerebroventricularly for 7 days (n=6/group). Acute intraperitoneal rilmenidine induced greater depressor and bradycardic responses in BPH/2J than BPN/3J mice (Pstrain<0.01). Both responses were reduced by atropine pre-treatment, with the remaining hypotensive effect being small and comparable between strains (Pstrain=1.0). This suggests that vagally induced reductions in cardiac output were responsible for the hypotension. Chronic intracerebroventricularly infused rilmenidine reduced BP from baseline marginally in BPH/2J mice during the dark (active) period (-6.5 ± 2 mmHg; P=0.006). Chronic orally administered rilmenidine (1-12 mg/kg per day) also had minimal effect on 24-h BP in both strains (P>0.16). The sympathetic vasomotor inhibitory effect of rilmenidine is minimal in both strains and similar in hypertensive BPH/2J and BPN/3J mice. Thus, hypertension in BPH/2J mice is not likely mediated by greater neuronal activity in the RVLM, and agents such as rilmenidine would be an ineffective treatment for this form of neurogenic hypertension.

Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis

PubMed Central

Liao, Chun-De; Tsauo, Jau-Yih; Liou, Tsan-Hon

2016-01-01

Background Stellate ganglion blockade (SGB) is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs), such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated the use of noninvasive SGB for managing neuropathic pain or other disorders associated with sympathetic hyperactivity. Materials and Methods We performed a comprehensive search of the following online databases: Medline, PubMed, Excerpta Medica Database, Cochrane Library Database, Ovid MEDLINE, Europe PubMed Central, EBSCOhost Research Databases, CINAHL, ProQuest Research Library, Physiotherapy Evidence Database, WorldWideScience, BIOSIS, and Google Scholar. We identified and included quasi-randomized or randomized controlled trials reporting the efficacy of SGB performed using therapeutic ultrasound, transcutaneous electrical nerve stimulation, light irradiation using low-level laser therapy, or xenon light or linearly polarized near-infrared light irradiation near or over the stellate ganglion region in treating complex regional pain syndrome or disorders requiring sympatholytic management. The included articles were subjected to a meta-analysis and risk of bias assessment. Results Nine randomized and four quasi-randomized controlled trials were included. Eleven trials had good methodological quality with a Physiotherapy Evidence Database (PEDro) score of ≥6, whereas the remaining two trials had a PEDro score of <6. The meta-analysis results revealed that the efficacy of noninvasive SGB on 100-mm visual analog pain score is higher than that of a placebo or active control (weighted mean difference, −21.59 mm; 95% CI, −34.25, −8.94; p = 0.0008). Conclusions Noninvasive SGB performed using PAMs effectively relieves pain of various etiologies, making it a valuable addition to the contemporary pain management armamentarium. However, this evidence is limited by the potential risk of bias. PMID:27911934

Anxiolytic Treatment Impairs Helping Behavior in Rats

PubMed Central

Ben-Ami Bartal, Inbal; Shan, Haozhe; Molasky, Nora M. R.; Murray, Teresa M.; Williams, Jasper Z.; Decety, Jean; Mason, Peggy

2016-01-01

Despite decades of research with humans, the biological mechanisms that motivate an individual to help others remain poorly understood. In order to investigate the roots of pro-sociality in mammals, we established the helping behavior test, a paradigm in which rats are faced with a conspecific trapped in a restrainer that can only be opened from the outside. Over the course of repeated test sessions, rats exposed to a trapped cagemate learn to open the door to the restrainer, thereby helping the trapped rat to escape (Ben-Ami Bartal et al., 2011). The discovery of this natural behavior provides a unique opportunity to probe the motivation of rodent helping behavior, leading to a deeper understanding of biological influences on human pro-sociality. To determine if an affective response motivates door-opening, rats receiving midazolam, a benzodiazepine anxiolytic, were tested in the helping behavior test. Midazolam-treated rats showed less helping behavior than saline-treated rats or rats receiving no injection. Yet, midazolam-treated rats opened a restrainer containing chocolate, highlighting the socially specific effects of the anxiolytic. To determine if midazolam interferes with helping through a sympatholytic effect, the peripherally restricted beta-adrenergic receptor antagonist nadolol was administered; nadolol did not interfere with helping. The corticosterone response of rats exposed to a trapped cagemate was measured and compared to the rats’ subsequent helping behavior. Rats with the greatest corticosterone responses showed the least helping behavior and those with the smallest responses showed the most consistent helping at the shortest latency. These results are discussed in terms of their implications for the interaction between stress and pro-social behavior. Finally, we observed that door-opening appeared to be reinforcing. A novel analytical tool was designed to interrogate the pattern of door-opening for signs that a rat’s behavior on one session influenced his behavior on the next session. Results suggest that helping a trapped rat has a greater motivational value than does chocolate. In sum, this series of experiments clearly demonstrates the fundamental role of affect in motivating pro-social behavior in rodents and the need for a helper to resonate with the affect of a victim. PMID:27375528

Impact of bromocriptine-QR therapy on cardiovascular outcomes in type 2 diabetes mellitus subjects on metformin.

PubMed

Chamarthi, Bindu; Ezrokhi, Michael; Rutty, Dean; Cincotta, Anthony H

2016-11-01

Type 2 diabetes mellitus (T2DM) is associated with a substantially increased risk of cardiovascular disease (CVD). Bromocriptine-QR (B-QR), a quick release sympatholytic dopamine D 2 receptor agonist, is a FDA-approved therapy for T2DM which may provide CVD risk reduction. Metformin is considered to be an agent with a potential cardioprotective benefit. This large placebo controlled clinical study assessed the impact of B-QR addition to existing metformin therapy on CVD outcomes in T2DM subjects. 1791 subjects (1208 B-QR; 583 placebo) on metformin ± another anti-diabetes therapy at baseline derived from the Cycloset Safety Trial, a 12-month, randomized, multicenter, placebo-controlled, double-blind study in T2DM, were included in this study. The primary CVD endpoint evaluated was treatment impact on CVD event rate, prespecified as a composite of time to first myocardial infarction, stroke, coronary revascularization, or hospitalization for unstable angina/congestive heart failure. Impact on glycemic control was evaluated as a secondary analysis. The composite CVD end point occurred in 16/1208 B-QR treated (1.3%) and 18/583 placebo treated (3.1%) subjects resulting in a 55% CVD hazard risk reduction (intention-to-treat, Cox regression analysis; HR: 0.45 [0.23-0.88], p = 0.028). Kaplan-Meier curves demonstrated a significantly lower cumulative incidence rate of the CVD endpoint in the B-QR treatment group (Log-Rank p = 0.017). In subjects with poor glycemic control (HbA1c ≥ 7.5) at baseline, B-QR therapy relative to placebo resulted in a significant mean %HbA1c reduction of -0.59 at week 12 and -0.51 at week 52 respectively (p < 0.001 for both) and a 10 fold higher percent of subjects achieving HbA1c goal of ≤7% by week 52 (B-QR 30%, placebo 3%; p = 0.003). These findings suggest that in T2DM subjects on metformin, BQR therapy may represent an effective strategy for reducing CVD risk. Cycloset Safety Trial registration: ClinicalTrials.gov Identifier: NCT00377676.

Sympathetic activity in chronic kidney disease patients is related to left ventricular mass despite antihypertensive treatment.

PubMed

Siddiqi, Laima; Prakken, Niek H; Velthuis, Birgitta K; Cramer, Maarten J; Oey, P Liam; Boer, Peter; Bots, Michiel L; Blankestijn, Peter J

2010-10-01

Chronic kidney disease (CKD) patients often have sympathetic hyperactivity, which contributes to the pathogenesis of hypertension and cardiovascular organ damage. Angiotensin-converting enzyme (ACE) inhibitors (ACEi) and angiotensin II receptor blockers (ARB) reduce sympathetic hyperactivity. Ideally, treatment should eliminate the relation between sympathetic activity and organ damage. The aim of the present study is firstly to compare left ventricular mass (LVM) of CKD patients using chronic ACEi or an ARB with LVM of controls. Secondly, we determine whether previously found muscle sympathetic nerve activity (MSNA) and arterial blood pressure during follow-up are predictive for the presence of increased LVM. Methods. We restudied 20 CKD patients and 30 healthy volunteers matched for age. Sympathetic nerve activity was quantified by the microneurography (MSNA). Arterial blood pressure was the mean of office blood pressure measurements. LVM was quantified by magnetic resonance imaging (MRI) without contrast. The period between MSNA and MRI measurements was 9 ± 3 years. All patients were treated according to guidelines with an ACEi or an ARB. In CKD patients, mean systolic and diastolic arterial pressure were 129 ± 10 and 84 ± 5 mmHg, respectively, during follow-up. In patients, as compared to controls, LVM was 93 ± 16 versus 76 ± 18 g, LVM index 30 ± 5 versus 24 ± 4 g/m(2.7) and mean wall thickness 11 ± 2 versus 9.0 ± 1 mm (all P < 0.01). Moreover, MSNA was related to LVM (r = 0.65, P < 0.002), LVM index (r = 0.46, P < 0.03) and LV mean wall thickness (r = 0.84, P < 0.001). Conclusions. In conclusion, the present study demonstrates that measures of LVM in CKD patients are greater than in healthy controls, despite a well-controlled blood pressure in the patients. Moreover, there is a positive relationship between these measures of LVM and MSNA, assessed years before, despite a standard antihypertensive treatment. These results support the notion that additional sympatholytic therapy could be beneficial.

Modulation of postjunctional α-adrenergic vasoconstriction during exercise and exogenous ATP infusions in ageing humans

PubMed Central

Kirby, Brett S; Crecelius, Anne R; Voyles, Wyatt F; Dinenno, Frank A

2011-01-01

Abstract The ability to modulate sympathetic α-adrenergic vasoconstriction in contracting muscle is impaired with age. In young adults, adenosine triphosphate (ATP) has been shown to blunt sympathetic vasoconstrictor responsiveness similar to exercise. Therefore, we tested the hypothesis that modulation of postjunctional α-adrenergic vasoconstriction to exogenous ATP is impaired in ageing humans. We measured forearm blood flow (FBF; Doppler ultrasound) and calculated vascular conductance (FVC) to intra-arterial infusions of phenylephrine (α1-agonist) and dexmedetomidine (α2-agonist) during rhythmic handgrip exercise (15% MVC), a control non-exercise vasodilator condition (adenosine), and ATP infusion in seven older (64 ± 3 years) and seven young (22 ± 1 years) healthy adults. Forearm hyperaemia was matched across all vasodilatating conditions. During adenosine, forearm vasoconstrictor responses to direct α1-stimulation were lower in older compared with young adults (ΔFVC =−25 ± 3%vs.−41 ± 5%; P < 0.05), whereas the responses to α2-stimulation were not different (−35 ± 6%vs.−44 ± 8%; NS). During exercise, α1-mediated vasoconstriction was significantly blunted compared with adenosine in both young (−9 ± 2%vs.−41 ± 5%) and older adults (−15 ± 2%vs.−25 ± 3%); however, the magnitude of sympatholysis was reduced in older adults (32 ± 13 vs. 74 ± 8%; P < 0.05). Similarly, α2-mediated vasoconstriction during exercise was significantly blunted in both young (−15 ± 4%vs.−44 ± 8%) and older adults (−26 ± 3%vs.−35 ± 6%), however the magnitude of sympatholysis was reduced in older adults (19 ± 8%vs. 60 ± 10%; P < 0.05). During ATP, both α1- and α2-mediated vasoconstriction was nearly abolished in young and older adults (ΔFVC ∼−5%), and the magnitude of sympatholysis was similar in both age groups (∼85–90%). Our findings indicate that the ability to modulate postjunctional α-adrenergic vasoconstriction during exercise is impaired with age, whereas the sympatholytic effect of exogenous ATP is preserved. Thus, if impairments in vascular control during exercise in older adults involve vasoactive ATP, we speculate that circulating ATP is reduced with advancing age. PMID:21486772

Prevention of Atrial Fibrillation by Bucindolol Is Dependent on the Beta1389 Arg/Gly Adrenergic Receptor Polymorphism

PubMed Central

Aleong, Ryan G.; Sauer, William H.; Davis, Gordon; Murphy, Guinevere A.; Port, J. David; Anand, Inder S.; Fiuzat, Mona; O’Connor, Christopher M.; Abraham, William T.; Liggett, Stephen B.; Bristow, Michael R.

2013-01-01

Objectives This study assessed the impact of bucindolol, a beta-blocker/sympatholytic agent, on the development of atrial fibrillation (AF) in advanced chronic heart failure with reduced left ventricular ejection fraction (HFREF) patients enrolled in the BEST (Beta-Blocker Evaluation of Survival Trial). Background β-Blockers have modest efficacy for AF prevention in HFREF patients. Bucindolol’s effects on HF and ventricular arrhythmic endpoints are genetically modulated by β1- and α2c-adrenergic receptor (AR) polymorphisms that can be used to subdivide HFREF populations into those with bucindolol effectiveness levels that are enhanced, unchanged, or lost. Methods BEST enrolled 2,708 New York Heart Association (NYHA) class III to IV HFREF patients. A substudy in which 1,040 patients’ DNA was genotyped for the β1-AR position 389 Arg/Gly and the α2c322–325 wild type (Wt)/deletion (Del) polymorphisms, and new-onset AF was assessed from adverse event case report forms or electrocardiograms at baseline and at 3 and 12 months. Results In the entire cohort, bucindolol reduced the rate of new-onset AF compared to placebo by 41% (hazard ratio [HR]: 0.59 [95% confidence interval (CI): 0.44 to 0.79], p = 0.0004). In the 493 β1389 arginine homozygotes (Arg/Arg) in the DNA substudy, bucindolol reduced new-onset AF by 74% (HR: 0.26 [95% CI: 0.12 to 0.57]), with no effect in β1389 Gly carriers (HR: 1.01 [95% CI: 0.56 to 1.84], interaction test = 0.008). When β1389 Gly carriers were subdivided by α2c Wt homozygotes (n = 413, HR: 0.94 [95% CI: 0.48 to 1.82], p = 0.84) or Del variant carriers (n = 134, HR: 1.33 [95% CI: 0.32 to 5.64], p = 0.70), there was a positive interaction test (p = 0.016) when analyzed with β1389 Arg homozygotes. Conclusions Bucindolol prevented new-onset AF; β1 and α2c polymorphisms predicted therapeutic response; and the 47% of patients who were β1389 Arg homozygotes had an enhanced effect size of 74%. (Beta-Blocker Evaluation in Survival Trial [BEST]; NCT00000560) PMID:24159564

Effect of bromocriptine-QR therapy on glycemic control in subjects with type 2 diabetes mellitus whose dysglycemia is inadequately controlled on insulin.

PubMed

Chamarthi, Bindu; Cincotta, Anthony H

2017-05-01

The concurrent use of an insulin sensitizer in type 2 diabetes mellitus (T2DM) patients with inadequate glycemic control on basal-bolus insulin may help improve glycemic control while limiting further insulin requirement. Bromocriptine-QR (B-QR), a quick release, sympatholytic, dopamine D2 receptor agonist therapy for T2DM, is a postprandial insulin sensitizer. This study evaluated the effect of B-QR on dysglycemia in T2DM subjects with suboptimal glycemic control on basal-bolus insulin plus metformin. The effect of once-daily morning administration of B-QR on dysglycemia was evaluated in 60 T2DM subjects derived from the Cycloset Safety Trial, with HbA1c >7% on basal-bolus insulin plus metformin at baseline, randomized to B-QR (N = 44) versus placebo (N = 16) and completed 12 weeks of study drug treatment. The analyses also included a subset of subjects on high-dose insulin (total daily insulin dose (TDID) ≥70 units; N = 36: 27 B-QR; 9 placebo). Subjects were well matched at baseline. After 12 weeks of B-QR treatment, mean % HbA1c decreased by -0.73% relative to baseline (p < 0.001) and by -1.13 relative to placebo (p < 0.001). In the high-dose insulin subset, B-QR therapy resulted in % HbA1c reductions of -0.95 and -1.49 relative to baseline (p < 0.001) and placebo (p = 0.001) respectively. Secondary analyses of treatment effect at 24 and 52 weeks demonstrated similar influences of B-QR on HbA1c. The fasting plasma glucose (FPG) and TDID changes within each treatment group were not significant. More subjects achieved HbA1c ≤7 at 12 weeks with B-QR relative to placebo (36.4% B-QR vs 0% placebo, Fisher's exact 2-sided p = 0.003 in the entire cohort and 37% vs 0%, 2-sided p = 0.039 in the high-dose insulin subset). B-QR therapy improves glycemic control in T2DM subjects whose glycemia is poorly controlled on metformin plus basal-bolus insulin, including individuals on high-dose basal-bolus insulin. This glycemic impact occurred without significant change in FPG, suggesting a postprandial glucose lowering mechanism of action. Cycloset Safety Trial registration: ClinicalTrials.gov Identifier: NCT00377676.

Comparison of the effects of moclobemide and selegiline on tyramine-evoked mydriasis in man

PubMed Central

Bitsios, P; Langley, R W; Tavernor, S; Pyykkö, K; Scheinin, M; Szabadi, E; Bradshaw, C M

1998-01-01

Aims To examine the feasibility of using the human iris in vivo for the assessment of the interaction between tyramine and monoamine oxidase (MAO) inhibitors. To examine the relative roles of the two forms of MAO in terminating the response to sympathomimetic amines in the iris, by comparing the effects of single oral doses of moclobemide, a selective MAO-A inhibitor, and selegiline, a selective MAO-B inhibitor, on mydriatic responses to tyramine. Methods Twelve healthy male volunteers participated in three monthly sessions, each associated with ingestion of one capsule (moclobemide 450 mg, selegiline 10 mg, or placebo), according to a double-blind, balanced, cross-over design. Tyramine hydrochloride eye-drops (75 mm, 2×10 μl) were instilled three times in the left conjuctival sac at 40 min intervals. Pupil diameter was monitored with a binocular infrared television pupillometer before and for 4.5 h after ingestion of the capsule. The pupillary response to tyramine was expressed as the area under the pupil diameter×time curve (arbitrary units). A blood sample was taken before and 2 h after ingestion of the capsule, for the assay of platelet MAO-B activity, and plasma 3,4-dihydroxyphenylglycol (DHPG) concentration, an index of MAO-A activity. Platelet MAO activity was assayed radiochemically, using [14C]-phenylethylamine as substrate, and plasma DHPG by high performance liquid chromatography (h.p.l.c.). The results were analysed using analysis of variance with repeated measures, followed by Bonferroni's corrected t-test, using a significance criterion of P < 0.05. Results Both moclobemide and selegiline, compared with placebo, caused significant miosis in the right (untreated) eye. The changes in pupil diameter (mm±s.e. mean) from the pretreatment measurement were: placebo −0.09±0.07, moclobemide −0.52±0.09, selegiline −0.26±0.1. The mydriatic response to tyramine was potentiated by moclobemide, compared with the response recorded in the presence of placebo. The responses to tyramine (arbitrary units±s.e. mean) were: placebo 77.08±11.65, moclobemide 140.25±18.9, selegiline 72.75±12.35. Both moclobemide and selegiline significantly reduced platelet MAO activity, compared with placebo. The changes in platelet MAO activity (nmol h−1 mg−1 protein±s.e. mean) from the pretreatment level were: placebo 0.5±0.62, moclobemide −6.7±0.66, selegiline −17.7±0.87. Moclobemide significantly reduced plasma DHPG concentration, compared with placebo. The changes in plasma DHPG concentration (nmol l−1±s.e. mean) from the pretreatment level were: placebo −0.01±0.24, moclobemide −4.98±0.32, selegiline −0.51±0.26. Conclusions The potentiation of tyramine-evoked mydriasis by moclobemide is likely to reflect the inhibition of MAO-A activity in the iris, consistent with the activity of this enzyme in sympathetic nerve terminals. The lack of effect of selegiline on tyramine-evoked mydriasis argues against a role of MAO-B in terminating the effects of sympathomimetic amines in the iris. The effects of the two drugs on platelet MAO activity and plasma DHPG concentration are in agreement with previous reports and consistent with the relative selectivity of moclobemide for MAO-A and of selegiline for MAO-B. The miosis caused by the two MAO inhibitors is likely to be due to a central sympatholytic action of the drugs. PMID:9663810

Effect of Locally Administered Dexmedetomidine as Adjuvant to Levobupivacaine in Supraclavicular Brachial Plexus Block: Double-blind Controlled Study.

PubMed

Bisui, Bikash; Samanta, Swastika; Ghoshmaulik, Sumanta; Banerjee, Amit; Ghosh, Tirtha R; Sarkar, Suman

2017-01-01

Brachial plexus block is effective with good postoperative analgesia in upper limb surgery has gained importance as it safe, low cost, and maintains stable hemodynamics intraoperatively. To decrease the onset time and prolong the duration of nerve block bicarbonate, opioids (morphine, fentanyl, etc.), sympathomimetic agents (epinephrine, phenylephrine, etc.), α-2 agonists (clonidine and dexmedetomidine), calcium channel blocker (verapamil), magnesium sulfate, etc., were studied with local anesthetics and their isomers. For their sedative, analgesic, perioperative sympatholytic, and cardiovascular stabilizing effects with reduced anesthetic requirements, α-2 adrenergic receptor agonists, such as more potent and highly selective dexmedetomidine, have been the focus of interest for regional anesthesia. Intravenous dexmedetomidine infusion resulted in significant opioid-sparing effects as well as a decrease in inhalational anesthetic requirements. Animal studies proved that dexmedetomidine enhances sensory and motor blockade along with increased duration of analgesia. In humans, dexmedetomidine has also shown to prolong the duration of block and postoperative analgesia when added to local anesthetic in various regional blocks. Bupivacaine, the widely used local anesthetic in regional anesthesia, is available in a commercial preparation as a racemic mixture (50:50) of its two enantiomers: levobupivacaine, S (-) isomer and dextrobupivacaine, R (+) isomer. Severe central nervous system and cardiovascular adverse reactions reported in the literature after inadvertent intravascular injection or intravenous regional anesthesia have been linked to the R (+) isomer of bupivacaine. The levorotatory isomers were shown to have a safer pharmacological profile with less cardiac and neurotoxic adverse effects. The decreased toxicity of levobupivacaine is attributed to its faster protein binding rate. The pure S (-) enantiomers of bupivacaine, i.e., ropivacaine and levobupivacaine were thus introduced into the clinical anesthesia practice. Such an increased usage mandates the documentation of evidence-based literature with regard to risk and safety concerns as well as clinical issues related to levobupivacaine. This study is designed to assess the efficacy of adding dexmedetomidine to levobupivacaine during placement of supraclavicular brachial plexus blockade. This prospective observational double-blinded study was conducted over a 1-year period among randomly selected seventy ( n = 35) American Society of Anesthesiologists Classes I and II patients of ages between 18 and 60 years of both sexes scheduled to undergo upper limb surgery. With nerve locator, levobupivacaine (0.5%) 28 ml and 2 ml normal saline for Group L and levobupivacaine (0.5%) 28 ml and 0.75 μg/kg dexmedetomidine made up a solution of 2 ml, for Group D, a total 30 ml will be injected locally, in both the groups. Onset and duration of sensory and motor block will be assessed. One patient in Group L and two patients in Group D failed to achieve block within 30 min. Those three patients were then excluded from the analysis. Hence, the analysis was done by taking 34 patients in Group L and 33 patients in Group D. Onset of sensory and motor block was earlier in Group D (12.03 ± 0.85 and 13.58 ± 0.97) than Group L (14.32 ± 1.15 and 15 ± 0.98), and the difference is statistically significant ( P < 0.0001). Duration of sensory and motor block was longer in Group D (563.94 ± 15.60 and 495.15 ± 10.34) than Group L (368.53 ± 9.89 and 321.47 ± 7.84), and the difference is also statistically significant ( P < 0.0001). Duration of analgesia was longer in Group D (672.12 ± 11.39) than Group L (506.47 ± 9.497), and the difference is statistically significant ( P < 0.0001). Heart rate and mean arterial pressure were well maintained within the presumed range of significant variation, i.e., 20% from baseline, though at some point of time, intergroup comparison was statistically significant. Visual analog scale score compared at the time for administration of rescue analgesic between the groups come out to be statistically significant. Addition of 0.75 μg/kg dexmedetomidine to 0.5% levobupivacaine for supraclavicular plexus block shortens sensory and motor block onset time and extends sensory block, motor block, and analgesia duration.