Plasma Norepinephrine Levels Research Articles

Metoprolol attenuates intracerebral hemorrhage-induced cardiac damage by suppression of sympathetic overactivity in mice

The high rates of mortality and disability resulting from intracerebral hemorrhage (ICH) are closely related to subsequent cardiac complications. The mechanisms underlying ICH-induced cardiac dysfunction are not fully understood. In this study, we investigated the role of sympathetic overactivity in mediating cardiac dysfunction post ICH in mice. Collagenase-injection ICH model was established in adult male C57BL/6J mice. Neurological function was subsequently evaluated at multiple time points after ICH and cardiac function was measured by echocardiography on 3 and 14 days after ICH. Plasma adrenaline, noradrenaline, cortisol and heart β1 adrenergic receptor (β1-AR) levels were assessed to evaluate sympathetic activity. Picro Sirius Red (PSR) staining was performed to evaluate cardiomyocyte hypertrophy and interstitial fibrosis. Monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interleukin-6(IL-6), nuclear factor kappa-B(NF-κB), NADPH oxidase-2 (NOX2), matrix metalloprotein (MMP-9) and transforming growth factor-beta (TGF-β) levels were assessed to evaluate inflammation, fibrosis and oxidative stress levels in heart after ICH. Macrophages and neutrophils were assessed to evaluate inflammatory cell infiltration in heart after ICH. ICH induced sympathetic excitability, as identified by increased circulating adrenaline, noradrenaline, cortisol levels and β1-AR expression in heart tissue. Metoprolol-treated ICH mice had improved cardiac and neurological function. The suppression of sympathetic overactivity by metoprolol attenuates cardiac inflammation, fibrosis and oxidative stress after ICH. In conclusion, ICH-induced secondary sympathetic overactivity which mediated inflammatory response may play an important role in post-ICH cardiac dysfunction.

Abstract P192: Orthostatic Tolerance Before And After 60 Days Of Strict Head Down Tilt Bedrest With And Without Daily Artificial Gravity Training

Background: Orthostatic intolerance occurs after space flight, immobilization and in patients with autonomic diseases, so there is a need for more effective countermeasures. We hypothesized that daily artificial gravity elicited through short-arm centrifugation attenuates plasma volume loss and orthostatic intolerance following 60 days of HDTBR, which models cardiovascular responses to weightlessness. Methods: We studied 24 healthy persons (8 women, 33.4±9.3 yr, 24.3±2.1 kg/m2) exposed to 60d HDTBR. Subjects were assigned to 30 min/d continuous short arm centrifugation (cAG), 6x5 min short arm centrifugation (iAG), or a control group (ctr, no countermeasures). Head-up tilt testing (15 min of 80°) followed by incremental lower body negative pressure (-10 mmHg every 3 min) until presyncope was performed before and at the end of HDTBR. Plasma volume was measured (CO rebreathing) 12-2 days before and after 56d of HDTBR. Stroke volume was measured by cMRI. Norepinephrine, epinephrine, aldosterone, and renine plasma levels were measured before and after HDTBR. Results: Time to presyncope decreased in all groups following bedrest (ctr: 22:56 min pre and 9:35 min post, cAG 15:34 min pre and 10:11 min post; iAG 14:56 min pre and 10:00 min post, p<0.001). The significant interaction (p=0.025) between bedrest and intervention was explained by greater baseline orthostatic tolerance time in the ctr. AG Data was pooled analysis. The reduction in stroke volume (ctr, pre: 93±19 ml, HDTBR: 69±13 ml, AG, pre: 88±20 ml, HDTBR: 67±17 ml) and plasma volume was similar (ctr, pre: 4155±1085 ml, HDTBR: 3855±1087 ml, AG, pre: 4114±1250 ml, HDTBR: 3674± 1313 ml). Catechols and aldosterone did not change significantly during bedrest. The increase in renine was similar between groups (ctr pre: 18±12 mE/L, HDTBR: 21±8 mE/L, AG pre: 21±10 mE/L, HDTBR: 31±12 mE/L). Conclusions: 30 min daily AG didn’t prevent a reduction in orthostatic tolerance following 60d HDTBR. Whether numerically smaller reductions in orthostatic tolerance in the AG groups indicate efficacy or result from baseline differences can’t be ascertained. A stronger AG stimulus or combination with other countermeasures might be required to maintain orthostatic tolerance and to attenuate the volume reduction.

Abstract P210: Central Blockade Of Tumor Necrosis Factor-Á-Converting Enzyme (tace) Ameliorates Neuroinflammation, Sympathetic Excitation And Cardiac Dysfunction In Heart Failure Rat

TACE is a key metalloprotease involved in ectodomain shedding of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-α. We previously reported that TACE-mediated production of TNF-α in the hypothalamic paraventricular nucleus (PVN) contributes to the sympathetic excitation in heart failure (HF). Additionally, the upregulated TGF-α in the PVN transactivates the epidermal growth factor receptor (EGFR) to activate extracellular signal-regulated kinase (ERK) 1/2 in HF. Here we sought to determine whether central inhibition of TACE attenuates neuroinflammation and prevents the progress of HF. Male rats underwent coronary artery ligation to induce HF or sham surgery (Sham). These rats were treated with bilateral PVN microinjection of a TACE siRNA or control siRNA while some rats received a 4-week intracerebroventricular (ICV) infusion of TACE inhibitor TAPI-0 or vehicle. Compared with Sham rats, HF rats treated with control siRNA, had higher (*P<0.05) levels of TNF-α (7.88±1.32* vs 2.77±0.98 pg/mL) and TGF-α (28.27±2.76* vs 11.62±2.48 pg/mL) in cerebrospinal fluid, and increased mRNA expression of TACE (2.53±0.30* vs 1.04±0.12), TNF-α (3.43±0.55* vs 1.03±0.11), TNF-α receptor 1 (2.32±0.27* vs 1.07±0.19), cyclooxygenase-2 (2.96±0.31* vs 1.10±0.19) and TGF-α (2.68±0.41* vs 1.06±0.14) in the PVN, but these levels were markedly reduced (39-54%*) in TACE siRNA-treated HF rats. Compared with control HF rats, HF rats treated with TACE siRNA had reduced expression of phosphorylated (p-) NF-κB p65 (1.27±0.14 vs 0.84±0.07*), p-EGFR (0.52±0.05 vs 0.37±0.04*) and p-ERK1/2 (1.06±0.10 vs 0.62±0.09*) in the PVN. Moreover, the elevated plasma norepinephrine levels, lung/body weight, heart/body weight and left ventricular (LV) end-diastolic pressure along with decreased LV dP/dt max in HF rats-treated with control siRNA were significantly attenuated in HF rats treated with TACE siRNA. Treatments with TACE siRNA in the PVN also improved the indicators of cardiac hypertrophy and fibrosis of HF. ICV infusion of TAPI-0 had the similar effects with PVN TACE siRNA on these variables in HF. These data indicate that central interventions suppressing TACE activity ameliorate neuroinflammation, sympathetic activation and cardiac dysfunction in HF.

Gastric Leiomyoma Misdiagnosed as a Left Cystic Adrenal Tumor

Gastrointestinal leiomyomas often occur in the esophagus, colon, and rectum, but are very rare in the stomach. The patient was referred to Jeju national university medical center for the treatment of a left adrenal tumor diagnosed 5 years ago. She had a long history of repeated left flank pain, nausea, and abdominal distension for the last few years. Annual follow-up computed tomography scan showed a no changed 5×5.5-cm sized multiloculated left adrenal cystic lesion. Laboratory tests revealed that the basal levels of plasma adrenocorticotropin, cortisol, aldosterone, renin, testosterone, adrenaline, noradrenaline, and dopamine were normal findings. The preoperative diagnosis was a left nonfunctioning adrenal neoplasm with symptom of discomfort. However, the tumor revealed as an exophytic growing leiomyoma with cystic changes of a stomach by surgery. The mass was found at the posterior wall of the fundus and about 5-cm-sized mass. Resection of the tumor was performed using laparoscopy. The pathologic diagnosis revealed a gastrointestinal leiomyoma with a benign cystic lesion lined by respiratory epithelium with an old hemorrhage and chronic gastritis. The patient had no evidence of recurrence during the 12-month follow-up. Gastric leiomyoma is unfamiliar to the usual urologists. It needs to take gastric leiomyoma into account if the left adrenal tumor is close to the stomach. Herein, we report the case of a 44-year-old woman with gastrointestinal leiomyoma misdiagnosing as a nonfunctioning adrenal tumor.

Changes in Gut Microbiota Induced by Doxycycline Influence in Vascular Function and Development of Hypertension in DOCA-Salt Rats.

Previous experiments in animals and humans show that shifts in microbiota and its metabolites are linked to hypertension. The present study investigates whether doxycycline (DOX, a broad-spectrum tetracycline antibiotic) improves dysbiosis, prevent cardiovascular pathology and attenuate hypertension in deoxycorticosterone acetate (DOCA)-salt rats, a renin-independent model of hypertension. Male Wistar rats were randomly assigned to three groups: control, DOCA-salt hypertensive rats, DOCA-salt treated with DOX for 4 weeks. DOX decreased systolic blood pressure, improving endothelial dysfunction and reducing aortic oxidative stress and inflammation. DOX decreased lactate-producing bacterial population and plasma lactate levels, improved gut barrier integrity, normalized endotoxemia, plasma noradrenaline levels and restored the Treg content in aorta. These data demonstrate that DOX through direct effects on gut microbiota and its non-microbial effects (anti-inflammatory and immunomodulatory) reduces endothelial dysfunction and the increase in blood pressure in this low-renin form of hypertension.

Changes in biochemical parameters in workers exposed to chemical production factors (heptane and hexane)

Introduction. Long-term constant exposure to certain representatives of aliphatic hydrocarbons during the extraction and processing of potash ore can lead to pathological changes on critical organs and systems in production workers. The study aims to evaluate the change in biochemical parameters in workers exposed to chemical production factors (heptane and hexane). Materials and methods. The study of the content of hexane, heptane in the air of the working area and the urine of workers, the establishment of changes in several biochemical (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, glutamyltransferase, epinephrine, and norepinephrine) and general clinical (eosinophils, neutrophils and the eosinophilia index) indicators, modeling of cause-and-effect relationships. Results. Specialists found in the observation group relative to the comparison group: increased levels of heptane and hexane in the urine up to 1.7 times; increased levels of adrenaline and norepinephrine in the blood plasma up to 1.8 times, up to 1.4 times ALAT and γ-GT in the blood serum, up to 1.9 times neutrophils in the nasal secretions associated with increased concentrations of heptane and hexane in the urine; an increase of up to 4.4 times in the frequency of diseases of the nervous system, respiratory organs, and digestion. Conclusions. In the air of the working area of the workers of the flotation shop of the sylvinite processing plant, the concentrations of the studied limit hydrocarbons were below the detection limit; there is an increased concentration of heptane and hexane in the urine. In the workers of the studied production, an increase of 1.4-1.8 times in the level of adrenaline and norepinephrine in blood plasma, 1.2-1.4 times in ALAT and γ-GT in blood serum, 1.9 times in the content of neutrophils in nasal secretions, which characterizes adverse effects from the respiratory, digestive and nervous systems. We proved the dependence of the increased frequency of diseases of the listed organs and systems on the increased concentration of heptane in the urine (R2=0.26-0.43; p=0.0001-0.028).

Influence of the prehospital administered dosage of epinephrine on the plasma levels of catecholamines in patients with out-of-hospital cardiac arrest

AimThis study evaluated whether the prehospital administered dosage of epinephrine (Ep) influences the plasma levels of catecholamines in patients with out-of-hospital cardiac arrest (OHCA). MethodsThis was a prospective, observational clinical study. Patients with OHCA transferred to our hospital between July 2014 and July 2017 were analyzed. The plasma levels of catecholamines were measured using blood samples obtained immediately upon arrival at the hospital and before the administration of Ep. Patients were divided into three groups based on the prehospital administered dosage of Ep: no prehospital administration (group Z); 1 mg of Ep (group O); and 2 mg of Ep (group T). The levels of catecholamines, as well as the conditions of resuscitation prior to and after arrival at the hospital were compared between the three groups. ResultsWe analyzed 145 patients with OHCA (96, 38, and 11 patients in groups Z, O, and T, respectively). Group T exhibited the highest plasma levels of Ep with a statistically significant difference, however, there were no significant differences in the plasma levels of norepinephrine (Nep), dopamine (DOA) and vasopressin (ADH) among the three groups. ConclusionThe prehospital administered dosage of Ep influences the plasma levels of Ep; however, it does not contribute to the plasma levels of Nep, DOA and ADH in patients with OHCA.

Effects On Exercise Intensity Associated With Catecholamine Dynamics And Changes In Mood During Yoga Session

The exercise intensity of Vinyasa yoga has been established to meet the criteria for moderate-to-vigorous physical activity reported in an ACSM Position Stand. Little is known about the effects of a single bout of Vinyasa yoga on the sympathetic nervous system and mood in beginners. PURPOSE: To determine the effects of a single bout of Vinyasa yoga on exercise intensity, catecholamine dynamics, and mood. METHODS: A 60-minute yoga session for beginners consisted of Vinyasa as the main component (34 minutes), with warm-up and cool-down exercises from Hatha Yoga. Sixteen healthy beginners (8 women, 8 men) performed exercise while wearing breath gas masks and heart rate monitors. Measures were mean metabolic equivalents (METs), oxygen consumption (VO2), heart rate (HR), and ratings of perceived exertion (RPE). Catecholamine dynamics were measured at pre- and post-rest, and at 55 minutes into the session. Pleasure was assessed using the Two-dimensional Mood Scale (TDMS) prior to the session and after the session. T-tests and analysis of variance were performed for analyses. RESULTS: Mean values across the entire yoga session for METs, HR, and RPE were 3.4 (± 0.5) METS; 100.8 (± 11.2) bpm; and 10.6 (± 1.7); respectively. Although maximal oxygen consumption was significantly lower in women subjects compared with men subjects, there were no significant differences in METs during the yoga session. A single bout of yoga caused a significant increase in circulating plasma norepinephrine levels (pre; 270 ± 146 pg/mL, post; 318 ± 140 pg/mL, p < 0.05), but not epinephrine or dopamine levels. Vitality and stability in the TDMS subscales were significantly increased following yoga (p < 0.01), suggesting that a single bout of yoga improved mood status. CONCLUSION: A light to moderate-intensity yoga session for beginners, which meets the ACSM criteria, is sufficient to affect sympathetic nervous system activity. Additionally, increased pleasure scores indicated improved mood.

Neurotransmitter Dysfunction in Irritable Bowel Syndrome: Emerging Approaches for Management.

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder whose aetiology is still unknown. Most hypotheses point out the gut-brain axis as a key factor for IBS. The axis is composed of different anatomic and functional structures intercommunicated through neurotransmitters. However, the implications of key neurotransmitters such as norepinephrine, serotonin, glutamate, GABA or acetylcholine in IBS are poorly studied. The aim of this review is to evaluate the current evidence about neurotransmitter dysfunction in IBS and explore the potential therapeutic approaches. IBS patients with altered colorectal motility show augmented norepinephrine and acetylcholine levels in plasma and an increased sensitivity of central serotonin receptors. A decrease of colonic mucosal serotonin transporter and a downregulation of α2 adrenoceptors are also correlated with visceral hypersensitivity and an increase of 5-hydroxyindole acetic acid levels, enhanced expression of high affinity choline transporter and lower levels of GABA. Given these neurotransmitter dysfunctions, novel pharmacological approaches such as 5-HT3 receptor antagonists and 5-HT4 receptor agonists are being explored for IBS management, for their antiemetic and prokinetic effects. GABA-analogous medications are being considered to reduce visceral pain. Moreover, agonists and antagonists of muscarinic receptors are under clinical trials. Targeting neurotransmitter dysfunction could provide promising new approaches for IBS management.

Relationship between the Plasma Levels of Catecholamines and Return of Spontaneous Circulation in Patients with Out-of-Hospital Cardiac Arrest.

Purpose The dynamic state of epinephrine (Ep) in the plasma of patients with out-of-hospital cardiac arrest (OHCA) remains unclear. The purpose of this study was to evaluate the relationship between the plasma levels of catecholamines (such as epinephrine (Ep), norepinephrine (Nep), and dopamine) and vasopressin (antidiuretic hormone (ADH)) and the acquisition of return of spontaneous circulation (ROSC) in OHCA patients. Methods This was a prospective, observational clinical study. Patients with OHCA transferred to our hospital between July 2014 and July 2017 were enrolled. The levels of catecholamines and ADH in the plasma were measured using blood samples immediately obtained on arrival at our hospital and before the administration of Ep. Patients in whom Ep was already administered prior to obtaining blood samples were excluded. Patients were divided into two groups: with and without ROSC, that is, ROSC (+) and ROSC (−) groups, respectively. The plasma levels of these agents and the conditions of resuscitation were compared between the two groups. Results A total of 96 patients with OHCA were analyzed. The ROSC (+) and ROSC (−) groups included 34 and 62 patients, respectively. There were no significant differences observed between the two groups in age, cause of cardiopulmonary arrest, and prehospital resuscitation time. The plasma levels of Ep and Nep were significantly lower in the ROSC (+) group than in the ROSC (−) group. However, there were no significant differences in the plasma levels of dopamine and ADH between the two groups. Conclusion Increased levels of Ep in the plasma may not be associated with the acquisition of ROSC in patients with OHCA.

Analytic and Integrative Framework for Understanding Human Sympathetic Arterial Baroreflex Function: Equilibrium Diagram of Arterial Pressure and Plasma Norepinephrine Level.

BackgroundThe sympathetic arterial baroreflex is a closed-loop feedback system for stabilizing arterial pressure (AP). Identification of unique functions of the closed system in humans is a challenge. Here we propose an analytic and integrative framework for identifying a static operating point and open-loop gain to characterize sympathetic arterial baroreflex in humans.Methods and ResultsAn equilibrium diagram with two crossing functions of mechanoneural (MN) and neuromechanical (NM) arcs was analyzed during graded tilt maneuvers in seven healthy subjects. AP and plasma norepinephrine level (PNE), as a surrogate for sympathetic nerve activity, and were recorded after vagal modulation of heart function was blocked by atropine. The MN-arc curve was described as a locus of operating points during –7, 0, 15, and 60° head-up tilting (HUT) on a PNE-AP plane. The NM-arc curve was drawn as a line between operating points before and after ganglionic blockade (trimethaphan, 0.1 mg⋅ml–1⋅kg–1) during 0° or 15° HUT. Gain values were estimated from the slopes of these functional curves. Finally, an open-loop gain, which is a most important index for performance of arterial baroreflex, was given by a product of the gain values of MN (GMN) and NM arcs (GNM). Gain values of MN was 8.92 ± 3.07 pg⋅ml−1⋅mmHg−1; and GNM at 0° and 15° HUT were 0.61 ± 0.08 and 0.36 ± 0.05 mmHg⋅ml⋅pg–1, respectively. A postural change from supine to 15° HUT significantly reduced the open-loop gain from 5.62 ± 0.98 to 3.75 ± 0.62. The effects of HUT on the NM arc and open-loop gain seemed to be similar to those of blood loss observed in our previous animal studies.ConclusionAn equilibrium-diagram analysis contributes to a quantitative and integrative understanding of function of human sympathetic arterial baroreflex.

Fast determination of 16 circulating neurotransmitters and their metabolites in plasma samples of spontaneously hypertensive rats intervened with five different Uncaria

This study aimed to establish a sensitive, reproducible, and rapid liquid chromatography method with tandem mass spectrometry detection to perform simultaneous quantitative analysis of 16 neurotransmitters and their metabolites in rat plasma, including levodopa, dopamine, norepinephrine, epinephrine, L-tryptophan, kynurenic acid, serotonin, melatonin, choline, acetylcholine, histamine, phenylethylamine, as well as excitatory (L-glutamic acid and L-aspartic acid) and inhibitory (γ-aminobutyric acid and L-glycine) neurotransmitters. These analytes were measured by ultra-high performance chromatography coupled with triple quadrupole mass spectrometry using a hydrophilic interaction chromatographic column (ethylene-bridged hybrid amide column). The internal standards of stable isotope labeling were used to improve the reliability of the results. Our method provided high linearity for all neurotransmitters (for all coefficients measured > 0.99), with inter- and intra-day accuracy from −14.82% to 17.49% and precision was between 0.89% and 17.70%. The method was subsequently verified in an animal study, where the intervention of five different Uncarias, the traditional Chinese medicine with hypotensive effects, was applied to the spontaneously hypertensive rats (SHRs). SHRs showed dysregulated plasma kynurenic acid, acetylcholine, and norepinephrine levels, and these neuroactive analytes were significantly restored by Uncaria treatment compared with the model group (SHR group). Compared with captopril, included as a positive control for its hypotensive effect, Uncaria had more effects on perturbing the levels of plasma neurotransmitters, which might indicate Uncaria’s potential in treating symptoms related to the nervous system. These results suggested that the changes in the neurotransmitters and their metabolites in plasma may be related to the pathogenesis of hypertension. It also provided valuable information about the action mechanisms of Uncaria on its hypotensive effects.

Predictors of the Pressor Response to the Norepinephrine Transporter Inhibitor, Atomoxetine, in Neurogenic Orthostatic Hypotension.

[Figure: see text].

Quantitative sensory testing and norepinephrine levels in REM sleep behaviour disorder – a clue to early peripheral autonomic and sensory dysfunction?

IntroductionStudies have reported autonomic impairment in patients with idiopathic REM sleep behaviour disorder (iRBD), which is considered a prodromal stage of alpha-synucleinopathies. It is still debated whether central or peripheral pathologies are first manifestations of alpha-synucleinopathies. This study aimed to characterize autonomic and somatosensory function in iRBD patients.MethodsThis cross-sectional prospective case–control study included 17 iRBD patients (mean age 66.3 ± 9.2 years) and 16 healthy controls (HCs, 66.6 ± 11.3 years). Quantitative sensory testing, neurological and neuropsychological assessments, norepinephrine blood plasma levels, tilt table examination with orthostatic blood pressure, and heart rate variability were carried out. Longitudinal data of 10 iRBD patients, including neurological, neuropsychological, and tilt table examination, were assessed.ResultsiRBD patients more frequently presented with orthostatic dysfunction than HCs (70.6% vs. 6.3%, p < 0.0001). Supine norepinephrine plasma levels were normal, but lower in iRBD (249.59 ± 99.78 pg/ml iRBD, 354.13 ± 116.38 pg/ml HCs, p < 0.05). Quantitative sensory testing revealed impaired cold (CDT) and vibration detection thresholds (VDT) on the foot in iRBD (CDT foot iRBD − 1.24 ± 0.31, HCs − 9.89E-17 ± 0.25, VDT iRBD − 1.11 ± 0.47, HCs − 1.46E-16 ± 0.25, p < 0.05). Cold detection thresholds differed between the foot and hand among iRBD patients (foot − 1.24 ± 0.31, hand − 0.56 ± 0.25, p < 0.05). Longitudinal data revealed an increase in maximum systolic and diastolic orthostatic blood pressure changes and a decrease in the Valsalva ratio in the follow-up group (p < 0.05).ConclusionThis study revealed autonomic dysfunction with somatosensory impairment, and decreased norepinephrine levels in iRBD, which may serve as a possible prodromal marker for developing alpha-synucleinopathy.

Auricular vagal nerve stimulation enhances gastrointestinal motility and improves interstitial cells of Cajal in rats treated with loperamide.

Gastrointestinal (GI) motility disorders affect a large proportion of the population with limited treatment options. The aims of this study were to investigate the potential of a non-invasive method of auricular vagal nerve stimulation (aVNS) for treating GI dysmotility and to explore possible mechanisms involving slow waves and interstitial cells of Cajal (ICC). Normal rats were treated daily with loperamide for 1 week and then treated, while still on daily loperamide, with aVNS/Sham-aVNS for another 1week. Gastric emptying (GE), small intestine transit (SIT), and GI slow waves were measured. The plasma level of pancreatic polypeptide (PP) and noradrenaline (NE) was assessed by ELISA. ICC in the gastric antrum were detected by immunohistochemistry. (a) aVNS significantly increased the percentage of normal GI slow waves (p<0.05 for both fasting and postprandial states, vs. Sham-aVNS) and accelerated GE (p<0.05, vs. Sham-aVNS) and SIT (p<0.05, vs. Sham-aVNS) impaired by loperamide. (b) aVNS increased plasma PP (p<0.01) and decreased plasma NE (p<0.01), compared with Sham-aVNS. (c) Gastric ICC was decreased by loperamide (p<0.01) but increased after aVNS (p<0.01, vs. Sham aVNS). Loperamide induces upper GI dysmotility. aVNS accelerates upper GI transit and improving pace-making activity mediated via the ICC. Non-invasive aVNS may have a therapeutic potential for upper GI dysmotility.

A Unique Presentation of a Paraganglioma and Its Consequences

Introduction: Paragangliomas (PGL) are extremely rare tumors arising from extra-adrenal neural crest cells with an incidence of 0.8 per 100,000 person-years. Sympathetic chain PGLs usually arise in the abdomen, with about 75% of them arising intra-abdominally [2]. On CT or MRI, PGLs are usually have homogenous enhancement or central areas of low attenuation. The consequences of PGLs are many, and one complication that is rarely noted is glycemic disturbances with catecholamine excess. Here, we present a case of a radiographically unique appearing PGL that resulted in dramatic improvement of diabetes after resection.Case: 41 year old male with a past medical history of diabetes, CKD and developmental delay presented with hyperglycemia. Patient’s home regimen of Glargine 15 units qHS and Humalog 5 units TID AC had run out a few days prior. Patient had Hemoglobin A1c of 11.8% mg/dL and a C-peptide of 0.4 ng/ml. Endocrine was initially consulted for glucose management. Hospital course was complicated by abdominal pain and CT imaging showed low attenuation splenic masses, retroperitoneal lymphadenopathy and a large, necrotic appearing mesenteric mass consistent with lymphoma. MRI reaffirmed mass with peripheral enhancement and central necrosis consistent with neoplasm.Patient underwent biopsy of lymphadenopathy, which came back benign and then went for biopsy of mass. As the needle entered the mass, the patient became acutely hypertensive and tachycardic. He received phentolamine with good response and labs were drawn for catecholamine producing tumor. Plasma norepinephrine level was 6048 pg/ml and a chromogranin level of 4788 ng/ml. An MIBG scan revealed focal uptake at the lesion without evidence of metastasis. In the subsequent weeks, he was alpha- and then beta-blocked and underwent resection of mass that was complicated by transient hypotension and hypoglycemia. Eventually, patient’s blood pressure was controlled and insulin requirements dropped precipitously to just requiring 4 units of glargine by discharge.Discussion: This patient had a mass on CT scan that appeared to be consistent with lymphoma as opposed to PGL that led to biopsy and subsequent catecholamine crisis. Fortunately, this was controlled and subsequent resection led to improvement in the patient’s glycemic control. It has been thought that glucose intolerance in PGL patients is due to impaired insulin release through desensitization of the beta-adrenergic receptor. Furthermore, Catecholamines, as counter-regulatory hormones, have been well documented to raise blood sugar on this basis as well. Fortunately for our patient, he survived an initial biopsy and post-operatively, was able to actually have an improvement in his glycemic control. It also is a reminder to always do a screen for PGL before doing a needle biopsy of a compatible abdominal mass.

Mixed Corticomedullary Tumors of the Adrenal Gland Harboring Both Medullary and Cortical Properties

Adrenal cortex and medulla are derived from mesoderm and ectoderm, respectively. Mixed corticomedullary tumors (MCMTs), comprising an intimately admixed population of both adrenal cortical cells and pheochromocytes in a single adrenal tumor, are extremely rare and its pathogenesis has remained unknown. Here, we report a case of MCMT whose cells co-expressed cortical and medullary antigens in the same tumor cells.[Case description]A 40-year-old woman was referred to our hospital for investigating Takotsubo cardiomyopathy following resection of uterine fibroids. An abdominal CT scan depicted a 24 mm tumor on her left adrenal gland. Her basal serum ACTH, cortisol levels and urinary cortisol were 13.8 pg/mL, 9.5 μg/dL, and 26.5 μg/day respectively. The cortisol level was normally suppressed by an administration of 1 mg dexamethasone (1.4 μg/dL). Plasma renin activity, aldosterone levels and urinary aldosterone were 15.0 ng/mL/h, 122 pg/mL, and 5.0 μg/day, respectively (with administration history of azosemide). On the other hand, her plasma adrenaline and noradrenaline levels were elevated as high as 177 pg/mL and 536 pg/mL, and urinary metanephrine and normetanephrine were 2.12 mg/day and 1.10 mg/day. A 123I-metaiodobenzylguanidine scan revealed high uptake in the tumor. After adequate adrenergic α-receptor blockage, left adrenalectomy was performed. Her postoperative endocrine and clinical findings were normalized without any further complications.[Pathology] Immunohistochemistry (IHC) revealed the presence of MCMT. Cells morphologically consistent with pheochromocytoma and adrenocortical cells were confirmed by immunostaining of chromogranin A and SF-1, respectively. Chromogranin A-positive medullary-derived and SF-1-positive cortical-derived tumor cells were intermixed in the chimeric fashion. In addition, some tumor cells were positive for both proteins, indicating hybrid nature of the cells. Tumor cells of cortical origin expressed CYP11β1, 3β-HSD, p450c21, and p450c17, but not CYP11β2. Non neoplastic adrenal cortex were atrophic, whereas the glomerulosa was hyperplastic positive for CYP11β2, consistent with diffuse hyperplasia and adrenal medullar unremarkable. [Conclusions:]The adrenal tumor was clinically diagnosed as pheochromocytoma, but the pathological findings did reveal cortisol production in the tumor and aldosterone overproduction in the accompanying cortex. This is the first case of MCMT co-expressing adrenal medullary and cortical antigens in the same tumor cells as hybrid cells.

Plasma dopamine and catecholamine levels in patients with central serous chorioretinopathy

To evaluate plasma dopamine and catecholamine levels in patients with central serous chorioretinopathy (CSCR). In this prospective study, 32 patients with acute CSCR were included, along with 32 age- and gender-matched healthy controls without CSCR. Complete ophthalmologic examinations were performed. Plasma dopamine, epinephrine, norepinephrine levels were measured in the morning after 8-12hours of fasting. A P-value of less than 0.05 was considered statistically significant. While the mean age of the CSCR group was 40.12±7.96 years, the mean age of the control group was 37.81±7.26 years. There was no statistically significant difference between the groups in terms of age or gender (P=0.229, P=0.740, respectively). The plasma dopamine level was 29.85±9.39pg/ml in the CSCR group and 23.93±7.33pg/ml in the control group (P=0.001). The plasma epinephrine level was 60.73±25.69pg/ml in the CSCR group and 45.77±18.55pg/ml in the control group (P=0.021). The plasma norepinephrine level was 206.68±71.51pg/ml in the CSCR group and 149.33±49.69pg/ml in the control group (P=0.001). Plasma dopamine, epinephrine, and norepinephrine levels were statistically significantly higher in the CSCR group. We concluded that dopamine may be a possible factor in the etiology of CSCR, both through its receptors and by enhancing sympathetic activity.

Attenuated β-adrenergic response in calcium/calmodulin-dependent protein kinase IV-knockout mice.

In the present study, we examined the importance of Ca2+/calmodulin-dependent protein kinase IV (CaMKIV) in the regulation of cardiac function using genetically modified CaMKIV-null mice. RT-PCR analysis revealed decreased expression of voltage-dependent calcium channels in the cardiac myocytes of CaMKIV-null mice compared with wild-type mice. CaMKIV-null mice showed shortened QT time on electrocardiograms. Pharmacological analysis revealed decreased responsiveness to the β-adrenergic blocker propranolol in CaMKIV-null mice, whereas the plasma norepinephrine level was not affected. CaMKIV-null mice showed decreased baroreflex on electrocardiograms. Heart rate variability analysis showed unstable R-R intervals, a decreased low frequency power/high frequency power (LF/HF) ratio, and increased standard deviation of the normal to normal R-R intervals (SDNN) in CaMKIV-null mice, suggesting decreased responsiveness to β-adrenergic stimulation in CaMKIV-null mice. Atrial contraction analysis and cardiac action potential recording showed a decreased response to the β-adrenoceptor agonist isoproterenol in CaMKIV-null mice. Furthermore, fluorescence imaging in a CRE-hrGFP assay revealed a decreased response to isoproterenol in CaMKIV-null cardiac myocytes. Taken together, our data strongly suggest a significant effect of CaMKIV gene ablation on cardiac β-adrenergic signal transduction.

Pharmacokinetics and pharmacodynamics of ampreloxetine, a novel, selective norepinephrine reuptake inhibitor, in symptomatic neurogenic orthostatic hypotension

PurposeAmpreloxetine is a novel, selective, long-acting norepinephrine reuptake (NET) inhibitor being investigated as a once-daily oral treatment for symptomatic neurogenic orthostatic hypotension (nOH) in patients with autonomic synucleinopathies. The purpose of this study was to characterize the pharmacokinetic and pharmacodynamic profiles of ampreloxetine in this target population.MethodsPatients with nOH were enrolled in a multicenter, phase II clinical trial of ampreloxetine (NCT02705755). They received escalating doses over 5 days in the clinical research unit, followed by 20 weeks of open-label treatment and then a 4-week withdrawal. As neurochemical biomarkers of NET inhibition, we assayed plasma concentrations of norepinephrine (NE) and its main intraneuronal metabolite 3,4-dihydroxyphenylglycol (DHPG) pre- and post-ampreloxetine.ResultsThirty-four patients with nOH were enrolled. Plasma ampreloxetine concentrations increased with repeated escalating doses, with peak concentrations observed 6–9 h post-drug administration. The median ampreloxetine dose in the 20-week treatment phase was 10 mg once daily. Plasma ampreloxetine concentrations reached steady state by 2 weeks, with stable plasma levels over 24 h. No influence of age or renal function on ampreloxetine plasma concentrations was observed. On treatment, compared to baseline, plasma NE significantly increased by 71% (p < 0.005), plasma DHPG significantly declined by 22% (p < 0.05), and the NE:DHPG ratio significantly increased (p < 0.001).ConclusionsPersistent elevation of plasma NE levels accompanied by reduced DHPG levels after ampreloxetine suggests reduced neuronal reuptake and metabolism of NE in postganglionic efferent sympathetic neurons. The findings are consistent with long-lasting NET inhibition, which may increase vasoconstrictor tone, supporting once-daily ampreloxetine dosing in patients with nOH.