Norepinephrine Levels Research Articles

Clinical analysis of robotic-assisted surgery in the treatment of large pheochromocytoma/paraganglioma: a study of 29 cases

This study aimed to compare the safety and clinical efficacy of Da Vinci robotic surgery (control group) versus traditional laparoscopic surgery in the treatment of large (tumor size >6 cm) pheochromocytomas/paragangliomas. The evaluation was based on intraoperative metrics such as operative time, blood loss, conversion to open surgery rates, postoperative drain duration, and length of postoperative hospital stay. A retrospective analysis was conducted on 29 patients (14 males and 15 females) who underwent Da Vinci robotic surgery for large (greater than 6 cm) pheochromocytomas/paragangliomas from October 2019 to September 2023. The average maximum tumor diameter was (7.2±1.6) cm. During the same period, 32 patients underwent laparoscopic resection of challenging pheochromocytomas/paragangliomas.Data showed no significant differences between the two groups, except for the norepinephrine levels. Operative time, blood loss, conversion rate, postoperative drainage duration, and length of hospital stay were recorded and compared between the two groups. The differences between the groups were analyzed using the t-test, and the conversion rates were compared using the chi-square (χ²) test. All surgeries were successfully performed. One patient underwent a one-stage bilateral tumor resection. In the Da Vinci robotic surgery group, the average operative time was (76±32) minutes, compared to (106±45) minutes in the control group (P=0.003). The average intraoperative blood loss was (95±75) ml, compared to (160±90) ml in the control group (P=0.019). The conversion rate to open surgery was 2 cases (6.9%) in the robotic group compared to 5 cases (15.6%) in the control group (P=0.031). The average postoperative drainage duration was (3.0±1.0) days, compared to (3.5±1.5) days in the control group (P=0.128). The average length of hospital stay was (4.5±1.2) days, compared to (4.7±2.2) days in the control group (P=0.657). Postoperative pathological diagnosis confirmed pheochromocytoma or paraganglioma. Blood pressure normalized within 1 to 3 months postoperatively, with an average systolic blood pressure of (116±13) mmHg(1 mmHg=0.133 kPa）and diastolic blood pressure of (73±5) mmHg in the robotic surgery group. Follow-up for 3 to 40 months showed normal levels of blood catecholamines and no recurrence or metastasis on follow-up imaging studies, including chest, abdominal, and pelvic CT scans. The average levels of 3-methoxy-norepinephrine, 3-methoxy-epinephrine, and 3-methoxy-tyramine were (0.42±0.21) nmol/L (normal value≤1.05 nmol/L), (0.11±0.07) nmol/L (normal value≤0.32 nmol/L), and (0.017±0.006) nmol/L (normal value≤0.036 nmol/L), respectively. This study demonstrates that for the treatment of large pheochromocytomas/paragangliomas, the Da Vinci robotic technique offers advantages such as high-definition visualization, precise operation, and flexibility. These advantages enable the safe and efficient completion of surgeries, as evidenced by shorter operative times, less blood loss, and lower conversion rates.

The impact of inflammatory and oxidative stress biomarkers on the sympathetic nervous system in severe coronary atherosclerosis.

The present study aimed at evaluating the association between sympathetic nervous system activation (SNS) and the severity of coronary artery disease (CAD). In addition, we tested the hypothesis that inflammation and oxidative stress influence the SNS activation. Adult patients with severe CAD scheduled for coronary artery bypass graft (CABG) surgery were enrolled. SYNTAX I score was calculated based on coronary angiography. Systemic activation of the SNS was estimated through circulating levels of norepinephrine (NE). Plasma levels of pro-inflammatory cytokines (IL 1β, IL 6 and HIF 1α) and oxidative stress molecules (SOD-1 and LOX-1) were obtained prior to surgery. Circulating NE levels were significantly correlated with the severity of CAD, as assessed by the SYNTAX I score (p 0.002; r 0.329). Elevated levels of circulating pro-inflammatory markers were significantly correlated with increased NE concentrations (for IL-1β: p < 0.001, r = 0.49; for IL-6 and NE: p = 0.003, r = 0.32; for HIF-1α and NE: p = 0.049, r = 0.21). Additionally, oxidative stress molecules were associated with circulating NE levels (for SOD-1 and NE: p = 0.016, r = 0.26; for LOX-1 and NE: p = 0.004, r = 0.31). In patients with CAD referred for CABG, SNS activation, indicated by plasma NE levels, was correlated with disease severity as assessed by the SYNTAX I score, as well as with markers of inflammation and oxidative stress. This suggests that inflammation, oxidative stress, and SNS activation form an interconnected network, with each component influencing the others. It might be of interest to develop a scoring system including inflammation and oxidative stress markers to identify patients that require a more aggressive approach to lower inflammation, oxidative stress and modulate the sympathetic nervous system. This could be of use especially in the setting of a scheduled intervention -such as CABG surgery.

Acupuncture at stellate ganglion combined with western medication for orthostatic hypotension in Parkinson's disease: a randomized controlled trial

To observe the effect of acupuncture at stellate ganglion on orthostatic hypotension (OH) in Parkinson's disease (PD), and explore its action mechanism. A total of 68 patients with OH in PD were randomly divided into a combination group (34 cases, 2 cases dropped out, 1 case was eliminated) and a western medication group (34 cases, 1 case was eliminated). Both groups received stable dose anti-PD western medication, the western medication group received oral midodrine hydrochloride tablets, 2.5 mg each time, 2 times a day. The combination group was treated with acupuncture at bilateral stellate ganglion on the basis of the western medication group, without retaining needles, once a day, 5 times a week. Both groups were treated for 2 weeks. Supine and orthostatic blood pressure, orthostatic hypotension questionnaire (OHQ) score, TCM syndrome score, unified Parkinson's disease rating scale (UPDRS) score before and after treatment in the two groups were observed, the level of serum norepinephrine (NE) was detected, and the clinical effect was evaluated. After treatment, orthostatic systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the combination group were increased compared with those before treatment (P<0.01), OHQ score, TCM syndrome score, UPDRS score were decreased compared with those before treatment (P<0.01); supine SBP in the western medication group was increased compared with that before treatment (P<0.05), OHQ score was decreased compared with that before treatment (P<0.05); the levels of serum NE in both groups were increased compared with those before treatment (P<0.01). After treatment, orthostatic SBP, orthostatic DBP and the level of serum NE in the combination group were higher than those in the western medication group (P<0.01, P<0.05), the OHQ score, TCM syndrome score, UPDRS score were lower than those in the western medication group (P<0.05, P<0.01). The total effective rate was 87.1% (27/31) in the combination group, which was higher than 63.6% (21/32) in the western medication group (P<0.05). Acupuncture at stellate ganglion can increase the orthostatic blood pressure in patients with OH in PD , improve clinical symptoms, and the mechanism may be related to the up-regulation of NE.

6701 Bilateral Adrenal Hematomas As Initial Presenting Sign Of Lung Adenocarcinoma

Abstract Disclosure: S. Gumireddy: None. R. Panta: None. Y. Shaikh: None. Introduction: Lung cancer typically presents with dyspnea, chest pain, hemoptysis, weight loss, or recurrent pulmonary infections. This case illustrates primary lung adenocarcinoma presenting with abdominal pain and bilateral adrenal hematomas. Clinical Case: 51-year-old male presented to the emergency department with left sided abdominal pain persisting for one week. CT abdomen showed a left suprarenal mass measuring 4.5 x 5 x 4.3cm indicating an acute adrenal hematoma. An MRI showed a partially solid left adrenal lesion that had hemorrhaged and a 1.3cm hemorrhagic nodule in the right adrenal gland. The patient remained hemodynamically stable. Hormonal evaluation done while patient was in the hospital showed renin level 0.417ng/mL/hr, aldosterone level &amp;lt;1.0ng/dL, epinephrine level 312pg/mL, norepinephrine level 333pg/mL, cortisol 11.3, ACTH level 13, plasma metanephrine levels 93pg/mL, plasma normetanephrine levels 111.7pg/mL, DHEA-S 151mcg/dL, potassium 4.1mmol/L, raising concern for hypersecretion. Patient was discharged with plans for outpatient follow-up but was readmitted in two months due to worsening abdominal pain. Repeat imaging revealed an increase in size of adrenal lesions, measuring 3.3 x 3.6 cm within the right adrenal gland and a 6.7 x 6.3 cm heterogeneously enhancing lesion within the left adrenal gland concerning for metastatic disease to bilateral adrenals and to the ileum causing small bowel obstruction. Chest imaging showed a 2.2cm irregular right apical nodule. Subsequent hormonal evaluation showed normalization of plasma metanephrine levels at 15.8pg/mL, renin level 3.314ng/mL/hr, aldosterone level 4.3ng/dL, deoxycorticosterone level 4.8ng/dL, androstenedione level 40ng/dL, plasma normetanephrines 146.4pg/mL. The patient underwent left adrenal gland mass biopsy which showed metastatic poorly differentiated adenocarcinoma of pulmonary origin. Tumor cells were positive for keratin cocktail, TTF1 and synaptophysin supporting the morphologic interpretation. Patient is currently receiving treatment with carboplatin, pemetrexed, and pembrolizumab. Conclusion: Adrenal masses can be unilateral (85%) or bilateral (15%). While most unilateral adrenal masses are benign and nonfunctional, bilateral adrenal masses are likely to be metastatic disease, hemorrhage, infiltrative disease, congenital adrenal hyperplasia, macronodular Cushing’s syndrome, or bilateral cortical adenomas. Although uncommon, our case highlights the importance of considering metastatic disease to the adrenal glands as a potential initial manifestation of primary cancers. The most likely primary cancers to metastasize to the adrenal glands are breast, lung, colon, kidney, and esophagus. Presentation: 6/1/2024

Mechanism of Treadmill Exercise Combined with Rich Environmental Stimulation to Improve Depression in Post-stroke Depression Model Rats.

Post-stroke depression (PSD) is a common complication, occurring in approximately one-third of these patients. The neurological symptoms of PSD affect patients' daily life and subsequent recovery. Analyzing the pathogenesis of post-stroke depression from a psychological perspective, it was found that PSD patients often feel despair and anxiety, and it is crucial to explore non-pharmacological ways to improve post-stroke depressive symptoms. A combination of exercise and rich environmental stimulation (RES) has been found effective in improving post-stroke depressive symptoms. Therefore, this study aimed to explore the effects of exercise and rich environmental stimulation on PSD in rats and their potential underlying mechanisms and to provide a theoretical basis for managing PSD. The PSD rat model was constructed, and the depression-like behaviors of rats in each group were evaluated using the open field test (OFT), sucrose preference test (SPT), and forced swimming test (FST). Moreover, changes in the morphological behavior of rat hippocampus were observed using hematoxylin-eosin (HE) staining and Nissl staining. The expression levels of 5-hydroxytryptamine (5-HT) and norepinephrine (NE) in hippocampus tissues were assessed using enzyme linked immunosorbent assay (ELISA), and the levels of tryptophan-related proteins were determined employing western blot analysis. Additionally, a kynurenine-3-monooxygenase (KMO) inhibitor was administered to the combined stimulation group, and the levels of tryptophan (TRP), 5-HT, kynurenine (KYN), 3-hydroxy-kynurenine (3-HK), and quinolinic acid (QA) were evaluated using liquid chromatography mass spectrometry/mass spectrometry (LC-MS/MS). Treadmill exercise combined with rich environmental stimulation significantly reduced the immobility time in the FST (p < 0.01), increased the exploratory behavior in the OFT (p < 0.05), and increased the sucrose water consumption in the SPT (p < 0.01), indicating that the depression-like behavior was improved. Treadmill exercise combined with rich environmental stimulation also improved the shape of the damaged hippocampus and increased the number of neurons in the hippocampus. Additionally, treadmill exercise combined with rich environmental stimulation significantly increased the levels of 5-HT and NE in hippocampus tissues (p < 0.01) and decreased KMO protein level (p < 0.01). In the KMO inhibitor group, the neural function was efficiently restored, the levels of 3-HK, QA, and KMO in the hippocampus were substantially reduced (p < 0.01), and the expression level of 5-HT was increased (p < 0.01). Exercise stimulation combined with enriched environmental stimuli alleviates post-stroke depression in rats, and the underlying mechanisms may be related to TRP/KYN/3-HK/QA excitotoxicity pathways and increased 5-hydroxytryptamine levels.

8688 Pseudopheochromocytoma Due To Severe Obstructive Sleep Apnea

Abstract Disclosure: L.M. José: None. M. Ataide: None. F. Aratani: None. S. Beeby: None. G.F. Fagundes: None. F. Coelho: None. F. Ledesma: None. A. Latronico: None. B.B. Mendonca: None. M.C. Fragoso: None. M.Q. Almeida: None. Background: Obstructive sleep apnea (OSA) represents an independent risk factor for cardiovascular disease, and it is associated with a wide range of conditions, such as resistant hypertension and primary aldosteronism (PA). Patients with sleep apnea have a higher sympathetic activity during wakefulness due to chronic hypoxia. We present the case of pseudopheochromocytoma caused by severe OSA in an obese patient with RH and PA.Clinical Case: A 58-year-old female Brazilian patient was referred to an endocrinologist to investigate a 1.8 cm right adrenal nodule at computed tomography (CT) performed to investigate abdominal pain. Her medical history includes resistant hypertension diagnosed at 27 years of age, type 2 diabetes, dyslipidemia, Class II obesity, a previous acute myocardial infarction, and severe OSA (apnea-hypopnea index 61.6/hour). She has used irregularly the continuous positive airway pressure (CPAP) therapy at night. She is currently using carvedilol 50 mg bid, chlorthalidone 25 mg, olmesartan 40 mg, amlodipine 10 mg, spironolactone 50 mg, clonidine 0.2 mg tid, hydralazine 50 mg every 6 hours, acetylsalicylic acid 100 mg, atorvastatin 80 mg, and metformin XR 1000 mg. At physical examination, she had BMI 37 kg/m2, BP 150 x 90 mmHg, HR 64 bpm, and no signs of Cushing syndrome. Abdominal CT revealed a right adrenal nodule measuring 1.8 cm with 18 Hounsfield unit (HU) in the pre-contrast phase, reaching a density of 117 HU at the arterial phase and showing an absolute washout of 65% and a relative washout of 56%. A nodular thickening of 1.4 cm (-4 HU) at the left adrenal gland was also displayed at CT scan. Hormone evaluation showed basal cortisol 7 µg/dL, ACTH 15.7 pg/mL, DHEAS 1152 ng/mL (189-2050 ng/mL), 1 mg overnight dexamethasone suppression test 2.3 ug/dL, aldosterone 9.9 ng/dL, direct renin concentration 36.8 uIU/mL, plasma metanephrines 0.3 nmol/L (&amp;lt;0.5 nmol/L) and plasma normetanephrines 1.3 nmol/L (&amp;lt;0.9 nmol/L). It was not possible to change anti-hypertensive medications to investigate PA. A 0.3 mg clonidine suppression test did not suppress normetanephrine levels, confirming the biochemical diagnosis of pheochromocytoma. Then, alpha-blockade with doxazosin 4 mg was started and the patient underwent right adrenalectomy. Pathological examination revealed an adenoma with immunohistochemistry positive for CYP11B2. BP control was achieved with only two medications and aldosterone decreased to 3 ng/dL confirming PA. Plasma normetanephrine levels remained elevated post-surgery and only normalized after the CPAP regular use.Clinical lessons: Chronic activation of sympathetic autonomic drive in OSA can increase norepinephrine and normetanephrine levels. OSA is a very prevalent disease and it is frequently associated with RH. Therefore, OSA should be considered a possible cause of pseudopheochromocytoma in hypertensive patients. Presentation: 6/3/2024

GC/MS and LC-ESI-MS Analysis of Conocarpus erectus Leaves Extract via Regulating Amyloid-β-Peptide, Tau Protein, Neurotransmitters, Inflammation and Oxidative Stress against AlCl3-Induced Alzheimer's Disease in Rats.

This study investigated the therapeutic effect of Conocarpus erectus leaves methanolic extract against AlCl3 -induced Alzheimer's disease (AD) in rats comparing with Donepezil-hydrochloride as a reference drug. The bioactive compounds of C. erectus leaves were isolated and identified by GC/MS and LC-ESI-MS analysis. Malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), amyloid-β-peptide (Aβ-peptide), tau protein, acetylcholinesterase (AChE), serotonin (5-HT), dopamine (DA) and nor-adrenaline (NE) levels were estimated. The neuromuscular strength, memory behavior and histopathological examination of cerebral cortex region were also conducted. Forty-three compounds were characterized from the non-polar fraction of C. erectus L. leaves extract and nineteen compounds were identified from the defatted extract. AlCl3- induction caused significant elevation of brain oxidative stress, Aβ-peptide, tau protein, IL-6, TNF-α and AChE levels. A significant decrease in 5-HT, ND and DA levels were noticed. Additionally, AlCl3 reduced neuromuscular strength and compromised memory function. Treatment of AlCl3- induced rats with C. erectuse extract ameliorated these selected parameters by variable degrees. In conclusion, C. erectus protects against AlCl3- induced AD in rats through its antioxidant, anti-inflammatory, and antineutron damage. It could be considered as a new nutraceutical agent for attenuating symptoms associated with Alzheimer's disease.

6579 Neuroendocrine Signatures of Social-Defeated Stress Expressed by Adrenal Hormones in Mice

Abstract Disclosure: J. Noh: None. J. Choi: None. S. Myung: None. M. Kim: None. M. Choi: None. While psychological stress is one of the prevalent contributors to depression, the precise role of metabolic phenotypes in the development of depression remains elusive. Abnormality in hypothalamus-pituitary-adrenal (HPA) axis is a classical feature of depression. Here, an animal model of social defeat stress (SDS) was established with five-week-old C57BL/6J mice to repeated episodes of social defeat for a period of 10 days, facilitated by an aggressive CD-1 mouse. Liquid chromatography-mass spectrometry-based profiling of 29 adrenocortical steroids and 6 medullary amines was employed for serum samples collected at 3, 5, 7, and 10 days during the modeling from both control (n = 28) and SDS (n = 32) group. In response to initial stress, corticosterone (B) and its two precursors were significantly increased (p &amp;lt; 0.03 for all) during 3 days, while 18-hydroxyB was remarkably elevated (p &amp;lt; 0.003 for 3 days and p &amp;lt; 0.005) in SDS mice. In contrast, dopamine (p &amp;lt; 0.03) and metanephrine (p &amp;lt; 0.008) were significantly increased during 5 days in SDS mice, while remarkably higher levels of norepinephrine were also observed during 7 days (p &amp;lt; 0.01). The SDS mice showed the increased levels of normetanephrine for all days of repeated stress exposure (p &amp;lt; 0.002 for all, except 10 days of p &amp;lt; 0.02). In this study, the HPA regulated negative feedback in short period, whereas sympathetic nervous system was continuously stimulated during repeated stress exposure. The present study may provide insight into the neuroendocrine effects of social stress on allostatic overload. Presentation: 6/2/2024

6891 Exclusive Normetanephrine Secreting Pheochromocytoma In A Young Male

Abstract Disclosure: E. Askar: None. H. Moran: None. IntroductionPheochromocytomas and paragangliomas arise from chromaffin cells and produce excessive catecholamines. Hypertension is their primary clinical symptom. they differ in their catecholamine secretory phenotype; paragangliomas typically secrete norepinephrine, while pheochromocytomas typically secrete epinephrine. Here, we present a case 21-year-old male with pheochromocytoma with elevated norepinephrine but normal epinephrine levels.Case presentationA 21 -year-old male with no past medical history presented with episodes of palpitations, sweating, and elevated blood pressure. He also reported abdominal pain. On admission, his blood pressure was 143/92 mmHg, pulse was 71/min, respiration was 16/min, and oxygen saturation was 100% in room air. The rest of physical exam was not significant. His electrolyte panel was normal. Computed tomography (CT) abdomen and pelvis with contrast was performed and showed a right adrenal mass measuring 4.9 x 4.0 x 6.5 cm which is predominantly hypoattenuating (approximately 30 Hounsfield units) with thick nodular rim of enhancement. Hormonal workup showed normal serum testosterone, DHEA-S, AM cortisol, ACTH, aldosterone, plasma metanephrine, and urine metanephrine, but profoundly high plasma normetanephrine 3641.6 (0.0-210.1) pg/mL. His 24-hour urinary normetanephrine was elevated at 14874 (80-440) ug/24hr, confirming a pheochromocytoma. The high norepinephrine level in the setting of normal epinephrine raised suspicion for Von Hippel Lindau (VHL). He was started on alpha and beta blockage and had laparoscopic removal of the right adrenal gland. The pathology report confirmed the diagnosis of pheochromocytoma confined to right adrenal. The patient was then referred for genetic testing. Conclusion: Pheochromocytoma can be a part of familial disorders, although being sporadic in nature most of the time. As demonstrated in our case, the hallmark of pheochromocytoma associated with VHL is nearly exclusive normetanephrine secretion and a high ratio of normetanephrine to metanephrine. Confirmation and testing of genes aid in proper monitoring and follow-up. The preferred course of treatment is radical resection. Presentation: 6/2/2024

Tyrosine hydroxylase-positive neurons in the rostral ventrolateral medulla mediate sympathetic activation in sepsis

AimSepsis results in high mortality and is associated with organ dysfunction caused by infection. The present study aimed to elucidate whether early-stage sympathetic activation is associated with the prognosis of sepsis and its possible mechanisms. MethodsPatients with sepsis and healthy controls were included. Sepsis in rats was induced by lipopolysaccharide. Dexmedetomidine, a α2-adrenergic receptor agonist, was used in patients and rats with sepsis to evaluate the role of the sympathetic nervous system in sepsis. Holter monitoring was used to detect heart rate variability, while plasma samples were obtained to measure levels of norepinephrine and inflammatory markers. Mean arterial pressure, heart rate, and renal sympathetic nerve activity were recorded. Immunofluorescence was used to detect the activation of neurons in the rostral ventrolateral medulla (RVLM). ResultsIn patients with sepsis, plasma levels of norepinephrine and interleukin-1β were higher compared with those in controls and positively correlated with acute physiology and chronic health evaluation (APACHEII). SDNN and SDANN were significantly reduced as well as negatively correlated with APACHEII. Meanwhile, rats with sepsis showed increased of sympathetic outflow and plasma levels of norepinephrine, with increased c-fos levels in the RVLM. Treatment with dexmedetomidine could improve prognosis. Lesion of tyrosine hydroxylase-positive neurons in the RVLM attenuated sympathetic activation and target organs damage in septic rats as well as improved survival. ConclusionThe results suggest that tyrosine hydroxylase-positive neurons in the RVLM might contribute to the prognosis of sepsis via activation of the sympathetic nervous system, while dexmedetomidine could ameliorate sepsis via inhibiting sympathetic activation.

Hand cooling induces changes in the kinetics of oxygen uptake

The objective of this investigation was to assess the impact of elevated catecholamine concentrations, induced through cold-water hand immersion, on the oxygen consumption (V̇O2) kinetics during intense exercise, and to contrast this effect with that of the priming effect. Ten active participants underwent three 8-minute constant work rate exercises (CWR) at ∆25%, with one CWR preceded by hand cooling (2 min at 0 °C, HC) and two consecutive CWR to induced priming effect on the second bout (SB). Pulmonary gas exchange and blood samples were analyzed to measure levels of epinephrine (E) and norepinephrine (NE). Results demonstrated a significant increase in the primary phase amplitude of V̇O2 kinetics in response to both hand HC (33.9 mL.min−1.kg−1; CI [32.2;35.7], p < 0.001) and SB (34.6 mL.min−1.kg−1; CI [33.0;36.3], p < 0.001) relative to the control (32.7 mL.min−1.kg−1; CI [31.5;35.1]). Additionally, the amplitude of the V̇O2 slow component was reduced for both HC (3.2 mL.min−1.kg−1; CI [2.2;4.1], p = 0.018) and SB (2.9 mL.min−1.kg−1; CI [1.8;4.2], p = 0.009) in comparison to control (3.9 mL.min−1.kg−1; CI [2.9;4.2]). These findings suggest that the increase in E and NE induced by hand cooling prior to exercise modifies V̇O2 kinetics in a manner akin to the priming effect. This research underscores the potential role of catecholamines in facilitating the priming effect and its subsequent impact on V̇O2 kinetics. However, further studies are necessary to clearly establish this link.

Effects of dopamine β-hydroxylase inhibition in pressure overload-induced right ventricular failure.

Activation of the sympathetic nervous system is observed in pulmonary arterial hypertension patients. This study investigates whether inhibiting the conversion of dopamine into noradrenaline by dopamine β-hydroxylase (DβH) inhibition with BIA 21-5337 improved right ventricular (RV) function or remodeling in pressure overload-induced RV failure. RV failure was induced in male Wistar rats by pulmonary trunk banding (PTB). Two weeks after the procedure, PTB rats were randomized to vehicle (n = 8) or BIA 21-5337 (n = 11) treatment. An additional PTB group treated with ivabradine (n = 11) was included to control for the potential heart rate-reducing effects of BIA 21-5337. A sham group (n = 6) received vehicle treatment. After 5 weeks of treatment, RV function was assessed by echocardiography, magnetic resonance imaging, and invasive pressure-volume measurements before rats were euthanized. RV myocardium was analyzed to evaluate RV remodeling. PTB caused a fourfold increase in RV afterload which led to RV dysfunction, remodeling, and failure. Treatment with BIA 21-5337 reduced adrenal gland DβH activity and 24-h urinary noradrenaline levels confirming relevant physiological response to the treatment. At end-of-study, there were no differences in RV function or RV remodeling between BIA 21-5337 and vehicle-treated rats. In conclusion, treatment with BIA 21-5337 did not have any beneficial-nor adverse-effects on the development of RV failure after PTB despite reduced adrenal gland DβH activity.

Activated sympathetic nerve post stroke downregulates Toll-like receptor 5 and disrupts the gut mucosal barrier

The gut permeability significantly increases after ischemic stroke, partly due to disrupted mucosal barrier, but the mechanism remains elusive. Here, we found that the mucus disruption starts at 2h post stroke, whereas goblet cell functions remain intact. Meanwhile, the flagellated bacteria Helicobacter thrives and penetrates in the mucus layer. Elimination of the mucosal microbiota or transplantation of Helicobacter in germ-free mice reveals an important role of the mucosal microbiota in mucus disruption. The bacterial invasion is due to downregulated Toll-like receptor 5 (TLR5) and its downstream products flagellin-specific IgA and antimicrobial peptides. Knockdown of intestinal TLR5 increases the abundance of flagellated bacteria and exacerbates mucus injury. Intestinal TLR5 is downregulated by the activation of sympathetic nerve. Serum noradrenaline level is positively associated with flagellin level in patients with stroke and patients' prognosis. These findings reveal a neural pathway in which the sympathetic nerve disrupts the mucosal barrier, providing potential therapeutic targets for stroke injury.

Development and Validation of Stability Indicating HPLC Method for the Determination of Related Substances in Droxidopa Drug Substance.

Droxidopa, a synthetic amino acid precursor to norepinephrine, was licensed by the FDA in 2014 to treat neurogenic OH. The enzyme L-amino acid decarboxylase in sympathetic neurons converts Droxidopa to norepinephrine, which raises the amount of norepinephrine in the blood.1 Because noradrenaline crosses the blood-brain barrier poorly. Droxidopa is used to raise the concentration of noradrenaline in the brain instead of noradrenaline itself. It is recommended for the treatment of dopamine beta-hydroxylase deficiency, non-diabetic autonomic neuropathy, orthostatic dizziness, and lightheadedness in adult patients with symptomatic neurogenic orthostatic hypotension resulting from primary autonomic failure (Parkinson’s disease, multiple system atrophy, and pure autonomic failure.2-5 It is a synthetic analog of catecholamine acid that raises norepinephrine and epinephrine levels throughout the body by being immediately metabolized by dopa-decarboxylase. In the CNS, it also penetrates the blood-brain barrier to carry out its pharmacological actions. Through the induction of peripheral arterial and venous vasoconstriction, it raises blood pressure peripherally and causes slight, momentary increases in plasma norepinephrin.

Aging disrupts locus coeruleus-driven norepinephrine transmission in the prefrontal cortex: Implications for cognitive and motor decline.

The locus coeruleus (LC)-prefrontal cortex (PFC) circuitry is crucial for cognition, planning, posture and mobility. This study examines the role of norepinephrine (NE) in elucidating the neurobiological basis of age-related cognitive and motor declines. Aged mice exhibited reduced spatial learning, impaired memory, decreased physical endurance, and notable changes in locomotor behavior. The neurochemical foundations of these deficits were investigated through fast-scan cyclic voltammetry to measure NE release in the PFC and LC, both invivo and in brain slices. Additionally, oxygen levels were monitored as a proxy for PFC neuronal function, and NE levels were analyzed in the extracellular space via microdialysis and total content in the PFC. Aged mice exhibited a frequency-dependent increase in NE release in the PFC upon LC stimulation, suggesting alterations in neural responsiveness due to aging. We also recorded slower NE reuptake rates and increased NE content and neuronal activity, indicated by higher oxygen levels and facilitated neuron activation due to membrane depolarization recorded via whole-cell patch-clamp. To understand the basis for LC-driven NE surges in the PFC with aging, we examined the expression levels of two proteins critical for presynaptic NE release and NE reuptake: the α2a-adrenergic receptor and the NE transporter. Both showed a significant decrease in the PFC with aging. These findings support the concept that aging significantly alters the structural and functional dynamics within the LC-PFC neural circuit, impacting NE modulation and neuronal activity, which may underlie the observed declines in cognitive and motor functions in aging populations.

Evaluation of Anti-Depressant Potential of Standardized Hydroethanolic Extract of S. barbata D. Don Using Chronic Unpredictable Mild Stress Model

Background: S. barbata D. Don is a Chinese herb, that belongs to the family Lami-aceae. It has established traditional use in ethnomedicine for treating various ailments, includ-ing mood disorders and sleep disorders, which led to growing interest in exploring its neuro-logical potential, particularly as a potential anti-depressant agent. Aims: This study explores the anti-depressant potential of the HSBE utilizing a Chronic Un-predictable Mild Stress-induced depression model in mice. Additionally, the research aims to elucidate the underlying mechanisms of action. Methods: Swiss albino mice were subjected to a 3-week CUMS paradigm and subsequently administered HSBE at doses of 200 and 400 mg/kg via oral administration. The behavioral alterations were evaluated using the FST, TST, OFT, and SPT. Brain levels of serotonin, dopa-mine, and nor-epinephrine were estimated in different brain regions (cortex, hippocampus, and hypothalamus) to uncover the molecular mechanism. Additionally, assays for monoamine oxi-dase-A, monoamine oxidase-B, and antioxidant enzyme activities were conducted. Plasma ni-trite and corticosterone levels were also measured to get further insight into potential mecha-nisms underlying the anti-depressant effects of HSBE. Results: HSBE significantly ameliorated depressive-like behavior induced by CUMS para-digm, as evidenced by reduced immobility in FST and TST, increased locomotor activity in OFT, and improved sucrose preference in SPT. Neurochemical analysis revealed a significant increase in serotonin, dopamine, and norepinephrine levels in the cortex, hippocampus, and hypothalamus of HSBE-treated mice, implying a potential regulation of monoaminergic neuro-transmitter levels. Moreover, biochemical analyses demonstrated a significant inhibition of both MAO-A and MAO-B activity, contributing to the increase of the brain levels of neuro-transmitters. The administration of HSBE also led to a significant enhancement of antioxidant enzyme activities and reduced brain lipid peroxidation, indicating a pronounced antioxidant effect of HSBE. Furthermore, decreased plasma nitrite and corticosterone levels provided ad-ditional insights into HSBE's potential multi-targeted anti-depressant mechanism. Conclusion: This study indicates that HSBE exhibits robust anti-depressant properties, sup-ported by behavioral, neurochemical, and biochemical alterations. These findings underscore the therapeutic promise of HSBE as a natural intervention for depressive disorders, warranting further clinical exploration.

Neuroprotective effect of Lannea egregia Alkaloid-rich leaf extracts in streptozotocin-induced diabetic rats

BackgroundStudies suggest that medicinal plant extracts can help reduce the neuron degeneration associated with diabetes. In this study, the neuroprotective effect of the alkaloid-rich extract from the leaves of Lannea egregia was assessed in rats with diabetes induced by streptozotocin (STZ). MethodsLannea egregia alkaloid-rich analysis was carried out via a known procedure. The rats were randomly assigned into five treatment groups (n = 8): normal control, diabetic-induced rats (45 mg/kg STZ), and diabetic rats treated with low doses of Lannea egregia leaf alkaloid-rich extract (50 mg/kg b.w, LEL) and high (100 mg/kg b.w, LEH) (300 mg/kg and 150 mg/kg), and metformin (200 mg/kg). On 22nd day of the experiment, animals were sacrificed, and their blood and brains were collected for neuro-biomarker analysis. ResultsDiabetic-induced rats that received metformin, LEL and LEH exhibited considerably reduced levels of dopamine, serotonin, norepinephrine, NO, MDA, and AChE, BChE activities when compared to untreated diabetic animals. Additionally, rats with diabetes that received treatment with metformin, LEL and LEH displayed a noticeable increase in ENTPDase, Na/K ATPase, GST, CAT, GPx, and SOD activities when compared to the untreated diabetic rats. Histological examination revealed improved brain architecture in the treated groups in contrast to those in diabetic-induced rats. ConclusionThe alkaloid-rich extracts of Lannea egregia might be effective in normalizing brain damage caused by complications of diabetes mellitus.

Neuroprotective Effects of Bryophyllum pinnatum against Ketamine-Induced Neurotoxicity in Wistar Rats: Neurochemical, Oxidative Stress, and Histological Investigation

Background: This study evaluated the neuroprotective effects of Bryophyllum pinnatum (B. pinnatum) in ketamine-induced neurotoxicity in Wistar rats, focusing on neurochemical and oxidative stress markers, as well as histological changes in the hippocampus and cerebral cortex. Methods: Sixty male Wistar rats were divided into six groups. Group 1 received normal saline (2ml), Group 2 was administered ketamine (20mg/kg), and Group 3 received risperidone (0.5mg/kg). Groups 4, 5, and 6 were treated with B. pinnatum at 50mg/kg, 100mg/kg, and 200mg/kg, respectively for a duration of 21 days after induction of toxicity. Neurochemical markers (dopamine, glutamate, GABA, serotonin, noradrenaline, acetylcholine), oxidative stress markers (GSH, MDA, SOD, CAT, GPx), and histological analysis of brain tissues were evaluated after treatment periods of one, two, and three weeks. Results: Ketamine administration significantly reduced dopamine, GABA, serotonin, and noradrenaline levels while increasing acetylcholine and glutamate levels (p&lt;0.05). B. pinnatum treatment reversed these effects in a dose-dependent manner, particularly at high doses. Oxidative markers showed reduced GSH and increased MDA levels with ketamine, which B. pinnatum mitigated significantly (p&lt;0.05). Histologically, ketamine caused neuronal degeneration and microstructural distortion in the hippocampus and cerebral cortex, which were markedly reduced by B. pinnatum, especially at 200mg/kg, showing well-preserved neuronal structures. Conclusion: B. pinnatum demonstrates significant neuroprotective effects against ketamine-induced neurotoxicity by modulating neurochemical and oxidative markers and preserving histological integrity in brain tissues, suggesting its potential therapeutic application in neurotoxic conditions.

The protective effects of chitosan and curcumin nanoparticles against the hydroxyapatite nanoparticles-induced neurotoxicity in rats

Hydroxyapatite nanoparticles (HANPs) have extensive applications in biomedicine and tissue engineering. However, little information is known about their toxicity. Here, we aim to investigate the possible neurotoxicity of HANPs and the possible protective role of chitosan nanoparticles (CNPs) and curcumin nanoparticles (CUNPs) against this toxicity. In our study, HANPs significantly reduced the levels of neurotransmitters, including acetylcholine (Ach), dopamine (DA), serotonin (SER), epinephrine (EPI), and norepinephrine (NOR). HANPs significantly suppressed cortical expression of the genes controlling mitochondrial biogenesis such as peroxisome proliferator activator receptor gamma coactivator 1α (PGC-1α) and mitochondrial transcription factor A (mTFA). Our findings revealed significant neuroinflammation associated with elevated apoptosis, lipid peroxidation, oxidative DNA damage and nitric oxide levels with significant decline in the antioxidant enzymes activities and glutathione (GSH) levels in HANPs-exposed rats. Meanwhile, co-supplementation of HANP-rats with CNPs and/or CUNPs significantly showed improvement in levels of neurotransmitters, mitochondrial biogenesis, oxidative stress, DNA damage, and neuroinflammation. The co-supplementation with both CNPs and CUNPs was more effective to ameliorate HANPs-induced neurotoxicity than each one alone. So, CNPs and CUNPs could be promising protective agents for prevention of HANPs-induced neurotoxicity.

Impact of Dexmedetomidine on Hemodynamics, Plasma Catecholamine Levels, and Delirium Incidence Among Intubated Patients in the ICU--A Randomized Controlled Trial.

To investigate the impact of various sedative medications on hemodynamics and plasma levels of epinephrine (E) and norepinephrine (NE) in mechanically ventilated patients postoperatively in the intensive care unit (ICU). Ninety-seven patients admitted to the ICU undergoing postoperative mechanical ventilation with tracheal intubation and continuous analgesic sedation following general anesthesia were randomly assigned to either the observation group (dexmedetomidine) (n = 49) or the control group (propofol) (n = 48) in this randomized controlled trial. Upon transfer to the ICU, vital signs (heart rate [HR], respiratory rate [RR], mean arterial pressure [MAP]) were recorded prior to the initiation of the sedation treatment (T0), at one-hour post sedation (T1) and two hours following tracheal extubation (T2), plasma levels of epinephrine (E) and norepinephrine (NE) were measured at these time points. The incidence of delirium was recorded in both groups. MAP between the two groups at both T0 and T1 At T2 plasma NE and HR were found to be lower in the observation group compared to the control group (P < 0.001). Among the patients receiving antihypertensive medication in the ICU, NE levels were significantly lower in the observation group compared to the control group (P = 0.019) Among the patients not receiving antihypertensive medication, both NE (P < 0.001) and MAP (P = 0.001) levels were lower in the observation group compared to the control group. The incidence of delirium in the observation group (dexmedetomidine) was not significantly different from that in the control group (propofol). With dexmedetomidine sedation, blood pressure fluctuated less, plasma catecholamine levels were lower, and sympathetic inhibition was stronger in patients before and after extubation. However, it did not significantly reduce the incidence of postoperative delirium.