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1.
Nihon Yakurigaku Zasshi ; 155(3): 135-139, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32378629

RESUMO

Stress potentiates craving for addictive drugs including cocaine. To elucidate neural mechanisms underlying this effect of stress, we developed an experimental paradigm combining cocaine-induced conditioned place preference (CPP) with a restraint stress. Acute restraint stress exposure immediately before posttest significantly increased cocaine CPP scores. It has been suggested that the extracellular noradrenaline (NA) level is increased by stress in the laterodorsal tegmental nucleus (LDT), which sends cholinergic projections to dopamine (DA) neurons in the ventral tegmental area (VTA), and medial prefrontal cortex (mPFC), which receives DA input from the VTA. Thus, we investigated the roles of NA in these brain regions. Intra-LDT injection of an α2 or a ß adrenoceptor antagonist attenuated the stress-induced enhancement of cocaine CPP. In vitro whole-cell recordings revealed that α2 adrenoceptor stimulation reduced GABAergic inputs to LDT cholinergic neurons that were obtained from cocaine-, but not saline-, treated rats. On the other hand, α1, but not α2 or ß, adrenoceptor stimulation excited mPFC pyramidal neurons. Intra-mPFC injection of an α1 adrenoceptor antagonist attenuated the stress-induced enhancement of cocaine CPP. Additionally, chemogenetic silencing of mPFC excitatory neurons also reduced the stress-induced enhancement of cocaine CPP. These findings suggest that stress-induced increases in neuronal activity of the LDT and mPFC may contribute to the enhancement of cocaine craving.


Assuntos
Neurônios Colinérgicos/patologia , Cocaína , Fissura , Estresse Psicológico , Animais , Condicionamento Psicológico , Norepinefrina/análise , Córtex Pré-Frontal , Ratos , Ratos Sprague-Dawley , Restrição Física , Tegmento Mesencefálico
2.
Am J Physiol Heart Circ Physiol ; 318(5): H1091-H1099, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32216617

RESUMO

The sympathetic nervous system modulates cardiac function by controlling key parameters such as chronotropy and inotropy. Sympathetic control of ventricular function occurs through extrinsic innervation arising from the stellate ganglia and thoracic sympathetic chain. In the healthy heart, sympathetic release of norepinephrine (NE) results in positive modulation of chronotropy, inotropy, and dromotropy, significantly increasing cardiac output. However, in the setting of myocardial infarction or injury, sympathetic activation persists, contributing to heart failure and increasing the risk of arrhythmias, including sudden cardiac death. Methodologies for detection of norepinephrine in cardiac tissue are limited. Present techniques rely on microdialysis for analysis by high-performance liquid chromatography coupled to electrochemical detection (HPLC-ED), radioimmunoassay, or other immunoassays, such as enzyme-linked immunosorbent assay (ELISA). Although significant information about the release and action of norepinephrine has been obtained with these methodologies, they are limited in temporal resolution, require large sample volumes, and provide results with a significant delay after sample collection (hours to weeks). In this study, we report a novel approach for measurement of interstitial cardiac norepinephrine, using minimally invasive, electrode-based, fast-scanning cyclic voltammetry (FSCV) applied in a beating porcine heart. The first multispatial and high temporal resolution, multichannel measurements of NE release in vivo are provided. Our data demonstrate rapid changes in interstitial NE profiles with regional differences in response to coronary ischemia, sympathetic nerve stimulation, and alterations in preload/afterload.NEW & NOTEWORTHY Pharmacological, electrical, or surgical regulation of sympathetic neuronal control can be used to modulate cardiac function and treat arrhythmias. However, present methods for monitoring sympathetic release of norepinephrine in the heart are limited in spatial and temporal resolution. Here, we provide for the first time a methodology and demonstration of practice and rapid measures of individualized regional autonomic neurotransmitter levels in a beating heart. We show dynamic, spatially resolved release profiles under normal and pathological conditions.


Assuntos
Técnicas Eletrofisiológicas Cardíacas/métodos , Coração/fisiologia , Miocárdio/metabolismo , Norepinefrina/análise , Amplificadores Eletrônicos/normas , Animais , Eletrodos/normas , Técnicas Eletrofisiológicas Cardíacas/instrumentação , Feminino , Masculino , Contração Miocárdica , Miocárdio/química , Norepinefrina/metabolismo , Sensibilidade e Especificidade , Suínos
3.
Mar Drugs ; 17(9)2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31443523

RESUMO

Abstract: α-Conotoxin TxIB is a specific antagonist of α6/α3ß2ß3(α6ß2*) nicotinic acetylcholine receptor (nAChR) with an IC50 of 28 nM. Previous studies have shown that α6ß2* nAChRs are abundantly expressed in midbrain dopaminergic neurons and play an important role in mediating the mechanism of nicotine and other drugs reward effect. It provided important targets for the development of anti-addiction drugs. The present study evaluated the pharmacological activity of TxIB in vivo with conditioned place preference (CPP) model, which were induced by subcutaneous injection (s.c.) of nicotine (NIC, 0.5 mg/kg). α-Conotoxin TxIB inhibited the expression and reinstatement of CPP in mice dose-dependently, but had no significant effect on locomotor activity. The concentrations of dopamine (DA), γ-aminobutyric acid (GABA) and noradrenaline (NE) in different brain regions were measured by enzyme-linked immunosorbent assay (ELISA). We found that TxIB could inhibit the concentrations of DA, GABA and NE in different brain regions (such as nucleus accumbens (NAc), hippocampus (HIP) and prefrontal cortex (PFC)) in NIC-induced mice. The concentrations of DA and NE were decreased in ventral tegmental area (VTA), while GABA had little change. The current work described the inhibition activity of TxIB in NIC-induced CPP, suggesting that α6ß2* nAChR-targeted compound may be a promising drug for nicotine addiction treatment.


Assuntos
Condicionamento Psicológico/efeitos dos fármacos , Conotoxinas/farmacologia , Antagonistas Nicotínicos/farmacologia , Receptores Nicotínicos/metabolismo , Tabagismo/tratamento farmacológico , Animais , Técnicas de Observação do Comportamento , Comportamento Animal/efeitos dos fármacos , Conotoxinas/uso terapêutico , Modelos Animais de Doenças , Dopamina/análise , Dopamina/metabolismo , Humanos , Injeções Subcutâneas , Ligantes , Masculino , Camundongos , Nicotina/administração & dosagem , Nicotina/efeitos adversos , Antagonistas Nicotínicos/uso terapêutico , Norepinefrina/análise , Norepinefrina/metabolismo , Recompensa , Área Tegmentar Ventral/química , Área Tegmentar Ventral/efeitos dos fármacos , Área Tegmentar Ventral/metabolismo , Ácido gama-Aminobutírico/análise , Ácido gama-Aminobutírico/metabolismo
4.
Medicine (Baltimore) ; 98(29): e16494, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31335714

RESUMO

RATIONALE: It is difficult to discriminate malignant pheochromocytoma (PCC) from benign PCC. The requirement of abdominal aortic and inferior vena cava reconstruction is extremely rare. PATIENT CONCERNS: We here report a case of a large pheochromocytoma in a 56-year-old woman who complained of only hand trembling and had no hypertension or other symptoms. The operation was difficult because of a tight adhesion to the circumference of great vessels. A replacement of the aortocaval vessels with grafts was necessary to remove the tumor completely. DIAGNOSES: Ultrasonography, computed tomography (CT), and catecholamine assay revealed suspecting the retroperitoneal PCC. INTERVENTIONS: Tumor excision and reconstruction of the abdominal aorta and inferior vena cava by externally supported polytetrafluoroethylene (ePTFE) vessels were successfully performed. OUTCOMES: A follow-up CT angiography showed no recurrence and graft vessels presented good patency after 7years. Catecholamine in urine and serum assay was normal. LESSONS: The complete resection of the tumor and infiltrated great vessels were necessary for the long-term survival of patients with a large PCC. The ePTFE graft is a good substitute for vessel reconstruction.


Assuntos
Aorta Abdominal/cirurgia , Implante de Prótese Vascular , Feocromocitoma/cirurgia , Neoplasias Retroperitoneais/cirurgia , Veia Cava Inferior/cirurgia , Aorta Abdominal/diagnóstico por imagem , Aorta Abdominal/patologia , Angiografia por Tomografia Computadorizada , Epinefrina/análise , Feminino , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , Norepinefrina/análise , Feocromocitoma/diagnóstico , Feocromocitoma/patologia , Politetrafluoretileno , Neoplasias Retroperitoneais/diagnóstico , Neoplasias Retroperitoneais/patologia , Resultado do Tratamento , Ultrassonografia , Veia Cava Inferior/diagnóstico por imagem , Veia Cava Inferior/patologia
5.
Eur Ann Otorhinolaryngol Head Neck Dis ; 136(4): 295-299, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31202665

RESUMO

OBJECTIVES: To present the 2017 Clinical Practice Guidelines of the French Society of Otorhinolaryngology concerning the role of the ENT specialist in the diagnosis of pediatric obstructive sleep apnea-hypopnea syndrome. This manuscript specifically focuses on diagnostic investigations apart from sleep studies. METHODS: A multidisciplinary work-group drew up a first version of the guidelines, graded according to level of evidence following the GRADE grading system. The final version was obtained by including the suggestions and comments from the editorial group. RESULTS: At the end of the process, guidelines were established and graded regarding diagnostic investigations apart from sleep studies, in particular respiratory functional tests, biological markers, and morphologic assessment under induced sleep (drug-induced sleep endoscopy (DISE) and cine-MRI).


Assuntos
Otorrinolaringologistas , Papel do Médico , Apneia Obstrutiva do Sono/diagnóstico , Biomarcadores/análise , Proteína C-Reativa/análise , Criança , Endoscopia/métodos , Epinefrina/análise , França , Humanos , Hipnóticos e Sedativos/uso terapêutico , Interleucinas/análise , Imagem por Ressonância Magnética , Norepinefrina/análise , Pediatria , Sistema Respiratório/diagnóstico por imagem , Sono , Sociedades Médicas , Taurina/análise , Tomografia Computadorizada por Raios X , Ácido gama-Aminobutírico/análise
6.
Anal Bioanal Chem ; 411(14): 3081-3089, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31076818

RESUMO

In this work, a facile and label-free ratiometric sensor is constructed for selective determination of norepinephrine (NE) by coupling second-order scattering (SOS) and fluorescence, two different and independent optical signals. Herein, polyethyleneimine (PEI) dilute solution medium shows an intensive SOS signal without any fluorescence response. Interestingly, NE can be selectively induced by PEI to emit bright fluorescence, and meanwhile causes an observable decrease in the SOS signal due to the interactions between NE and PEI. The simultaneous variation of the two independent signals can be used for ratiometric sensing of NE. Under the optimal conditions, the resultant ratiometric sensor displays high sensitivity and selectivity toward NE by simultaneously monitoring fluorescence and SOS signals with the same excitation wavelength. The proposed sensor exhibits a good linear relationship versus NE concentration in the range of 10.0 nM-45.0 µM with a detection limit of 2.0 nM (S/N = 3) and has been successfully applied to the determination of NE in real samples without the use of any extra reagent. The combination of fluorescence and SOS signals provides a new scheme for ratiometric sensor design, greatly simplifying experimental procedure and effectively enhancing detection accuracy. Moreover, the proposed analytical strategy further broadens the application of dilute solutions of polymers in research into optical sensor and green analytical chemistry. Graphical abstract.


Assuntos
Norepinefrina/análise , Óptica e Fotônica/instrumentação , Espalhamento de Radiação , Espectrometria de Fluorescência/métodos , Estudos de Viabilidade , Fluorescência , Luz , Limite de Detecção , Norepinefrina/normas , Norepinefrina/urina , Tamanho da Partícula , Polietilenoimina/química , Portulaca/química , Padrões de Referência
7.
ACS Chem Neurosci ; 10(4): 1872-1874, 2019 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-30920796

RESUMO

To overcome the limitations of fast scan cyclic voltammetry (FSCV) to discriminate between catecholamines, we discuss new approaches to monitor the dynamics of these neurochemicals with high spatial, genetic, and temporal specificity.


Assuntos
Catecolaminas/análise , Dopamina/análise , Técnicas Eletroquímicas/tendências , Aprendizado de Máquina/tendências , Norepinefrina/análise , Optogenética/tendências , Animais , Catecolaminas/metabolismo , Dopamina/metabolismo , Técnicas Eletroquímicas/métodos , Humanos , Norepinefrina/metabolismo , Optogenética/métodos
8.
Nanoscale ; 11(12): 5254-5264, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30864583

RESUMO

It is of great interest to design nanomaterial biosensors that can selectively detect target molecules without the use of fragile and expensive antibodies. Here, we report a chemical approach to modulate the response selectivity of graphene oxide (GO) fluorescence for neurotransmitters, in order to design an optical biosensor for the selective detection of dopamine without using antibodies. To this end, GO was functionalized with six different amino acids, followed by the immobilization of seven metal ions, resulting in the production of forty-two different GO nanohybrids (denoted GO-AA-MI derivatives). The fluorescence response of GO-AA-MI derivatives to dopamine, norepinephrine, and epinephrine was modulated by varying the type of amino acids and metal ions introduced. Tyrosine-modified GO with Fe2+ ions (GO-Y-Fe) exhibited selective quenching of its fluorescence in the presence of dopamine whereas lysine-modified GO with Au3+ ions (GO-K-Au) showed a selective increase in fluorescence upon addition of norepinephrine. The GO-Y-Fe sensor developed was able to differentiate dopamine from similar structures of norepinephrine and epinephrine, as well as abundant interferents such as ascorbic acid and uric acid, without the use of antibodies. In addition, the GO-Y-Fe sensor successfully detected dopamine secreted from living neuron cells in a rapid and simple manner.


Assuntos
Técnicas Biossensoriais/métodos , Corantes Fluorescentes/química , Grafite/química , Neurotransmissores/análise , Compostos Organometálicos/química , Aminoácidos/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Dopamina/análise , Epinefrina/análise , Corantes Fluorescentes/farmacologia , Microscopia de Força Atômica , Norepinefrina/análise , Células PC12 , Ratos , Ácido Úrico/química
9.
Ann Pharm Fr ; 77(3): 212-221, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30803767

RESUMO

OBJECTIVES: Norepinephrine is usually used in emergency situations such as in intensive care units (ICUs) for the restoration of blood pressure. The objective was to study the stability of highly-concentrated solutions of norepinephrine at 0.50mg/mL and 1.16mg/mL, diluted in glucose 5% (G5%) in polypropylene syringes, protected or not from light, up to 48h. MATERIALS AND METHODS: Chemical stability was analysed by high-performance liquid chromatography coupled to photodiode array detection at each time of the analysis. The method was validated according to the International Conference on Harmonisation Q2(R1). Physical stability was evaluated by visual and subvisual inspection. Three syringes for each condition were prepared. At each time of the analysis, three samples were analysed for each syringe. pH values were evaluated at each moment of the analysis. RESULTS: Solutions of norepinephrine at 0.50 and 1.16mg/mL, diluted in G5%, with or without protection from light, retained more than 95.0% of the initial concentration after a 48-hour storage at 20-25°C. No visual and subvisual modification occured during the stability study. No degradation product appearing during the stressed degradation was observed during the study but an additional peak with a relative retention at 0.66 was observed and constant. This peak was identified as 5-hydroxymethylfurfural, a degradation product of glucose. CONCLUSION: Norepinephrine diluted in G5% at 0.50mg/mL and 1.16mg/mL was physically and chemically stable over a period of 48hours at room temperature. These stability data of highly concentrated solutions provide additional knowledge to assist intensive care services in daily practice.


Assuntos
Unidades de Terapia Intensiva/estatística & dados numéricos , Norepinefrina/análise , Vasoconstritores/análise , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Furaldeído/análogos & derivados , Furaldeído/análise , Concentração de Íons de Hidrogênio , Luz , Norepinefrina/administração & dosagem , Polipropilenos , Reprodutibilidade dos Testes , Seringas , Temperatura , Vasoconstritores/administração & dosagem
10.
Med Sci Monit ; 25: 389-394, 2019 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-30636257

RESUMO

BACKGROUND Depression is a common disorder linked with high levels of chronicity, psycho-social and physical problems, and suicide. Here, we assessed the antidepressant effects of the hydromethanolic extract of Taraxacum officinale and investigated the underlying mechanism. MATERIAL AND METHODS Antidepressant effects were examined by use of the tail suspension test (TST). Concentrations of corticosterone, dopamine, noradrenaline, and adrenaline were examined by biochemical assays. The mRNA expression was assessed by quantitative RT-PCR. Phytochemical analysis was performed by LC/MS. RESULTS The results showed that the extract at the dosage of 50 and 100 mg/kg significantly (p<0.01) alleviated the TST-induced immobility in the mice, and the effects were comparable to the antidepressant drug Bupropion, which was used as the positive control. Investigation of the underlying mechanism revealed that the T. officinale extract exerts it effects by significantly (p<0.05) decreasing the levels of corticosterone and increasing the concentrations of dopamine, noradrenaline, and adrenaline. Further, the extract also increased the expression of brain-derived neurotrophic factor (Bdnf), which was associated with significant (p<0.05) decrease in the expression of mitogen-activated protein kinase phosphatase-1 (Mkp-1), indicative of the antidepressant potential of T. officinale. Finally, the active constituents of the extract, which include isoetin, hesperidin, naringenin, Kaempferol, sinapinic, and gallic acid, were also identified, which could potentially be responsible for its antidepressant effects. CONCLUSIONS In conclusion, T. officinale exerts significant antidepressant effects in a mouse model of depression by inhibition of corticosterone levels and modulation of Mkp-1 and Bdnf expression.


Assuntos
Depressão/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Taraxacum/metabolismo , Animais , Antidepressivos/uso terapêutico , Comportamento Animal/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Corticosterona/metabolismo , Depressão/metabolismo , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/fisiopatologia , Modelos Animais de Doenças , Dopamina/análise , Fosfatase 1 de Especificidade Dupla/efeitos dos fármacos , Fosfatase 1 de Especificidade Dupla/metabolismo , Epinefrina/análise , Masculino , Camundongos , Camundongos Endogâmicos ICR , Norepinefrina/análise , Fitoterapia/métodos , Extratos Vegetais/farmacologia , Folhas de Planta/metabolismo , Estresse Psicológico/metabolismo , Natação , Taraxacum/fisiologia
11.
Semin Pediatr Surg ; 28(6): 150859, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31931960

RESUMO

Neuroblastoma is a heterogenous disease, with solid tumors arising in the adrenal gland or paraspinal regions in young children. Neuroblastoma is unique, with varied presentation and prognosis based on primary location and tumor stage. Tumor behavior and response to treatment ranges from spontaneous regression to disseminated, lethal disease depending on the individual biology of a patient's tumor. Stratification of the disease has changed, with patients now placed in low, intermediate, and high-risk categories depending on age, stage, and tumor biology. Long-term survival for the high-risk subset of patients with metastatic disease is <40% despite aggressive multimodal therapy. Derived from sympathoadrenal cells of the adrenal medulla and sympathetic nervous system, both malignant neuroblastoma and differentiated tumors have specialized norepinephrine transporter (NET) receptors which are naturally occurring in the sympathetic nervous system throughout the body. Metaiodobenzylguanidine (MIBG) is a norepinephrine analog that undergoes active uptake by NET receptors resulting in accumulation in neuroblastoma as well as tissues normally expressing the NET receptor. When radioiodine labeled, MIBG can be used for both diagnosis and treatment. This article describes the history of MIBG use in neuroblastoma, including its utility as an imaging modality for diagnosis as well as the varied ways in which is it included in the multimodal treatment algorithm.


Assuntos
3-Iodobenzilguanidina , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/tratamento farmacológico , Antineoplásicos/uso terapêutico , Neuroblastoma/diagnóstico por imagem , Neuroblastoma/tratamento farmacológico , Norepinefrina/análise , Compostos Radiofarmacêuticos , 3-Iodobenzilguanidina/uso terapêutico , Criança , Humanos
12.
Pak J Pharm Sci ; 32(6): 2633-2641, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31969296

RESUMO

Camel milk is reported as anti-diabetic, hepato-protective, anticancer, antioxidant, antiviral and neuroprotectant in numerous studies. Based on its neuroprotective profile, camel milk is investigated for its possible beneficial effect in treating anxiety and depression and its effect on brain biogenic amines in the present study. Head dip, cage crossing, stationary rod, elevated plus-maze, open field, light & dark box and forced swim tests were used to measure change in rodents' behavior after camel milk administration. Any possible change in brain biogenic amines level after camel milk treatment was evaluated using High Performance Liquid Chromatography (HPLC) technique. Camel milk administration resulted in significant increase (p<0.001) in exploratory and locomotor activity and showing anxiolytic behavior in rodents. In depression-like model, rats showed significant increase (p<0.001) in struggling time after 30-days administration of camel milk. HPLC detection of brain biogenic amines revealed significant increase (p<0.001) in norepinephrine, insignificant increase in 5-hydroxytryptamine and significant decrease (p<0.001) in dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid in camel milk treated group. Based on above findings, camel milk is suggested as anxiolytic and antidepressant in the administered doses. However, further experimental and clinical investigations are required to authenticate the same at different doses.


Assuntos
Aminas Biogênicas/análise , Química Encefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Leite/química , Ácido 3,4-Di-Hidroxifenilacético/análise , Animais , Ansiolíticos/farmacologia , Antidepressivos/farmacologia , Camelus , Cromatografia Líquida de Alta Pressão , Dopamina/análise , Feminino , Ácido Homovanílico/análise , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Norepinefrina/análise , Ratos , Ratos Wistar , Serotonina/análise
13.
Anal Chem ; 90(22): 13348-13355, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30358389

RESUMO

Although fast-scan cyclic voltammetry (FSCV) has been widely used for in vivo neurochemical detection, the sensitivity and selectivity of the technique can be further improved. In this study, we develop fast cyclic square-wave voltammetry (FCSWV) as a novel voltammetric technique that combines large-amplitude cyclic square-wave voltammetry (CSWV) with background subtraction. A large-amplitude, square-shaped potential was applied to induce cycling through multiple redox reactions within a square pulse to increase sensitivity and selectivity when combined with a two-dimensional voltammogram. As a result, FCSWV was significantly more sensitive than FSCV ( n = 5 electrodes, two-way ANOVA, p = 0.0002). In addition, FCSWV could differentiate dopamine from other catecholamines (e.g., epinephrine and norepinephrine) and serotonin better than conventional FSCV. With the confirmation that FCSWV did not influence local neuronal activity, despite the large amplitude of the square waveform, it could monitor electrically induced phasic changes in dopamine release in rat striatum before and after injecting nomifensine, a dopamine reuptake inhibitor.


Assuntos
Técnicas Eletroquímicas/métodos , Neurotransmissores/análise , Animais , Corpo Estriado/metabolismo , Dopamina/análise , Epinefrina/análise , Masculino , Camundongos , Norepinefrina/análise , Ratos Sprague-Dawley , Sensibilidade e Especificidade , Serotonina/análise
14.
Analyst ; 143(21): 5247-5254, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30276380

RESUMO

Information on the dynamics of molecules following olfactory dysfunction remains essential for understanding the molecular events involved in the pathological process of olfactory dysfunction. This study for the first time demonstrates a method based on the combination of in vivo microdialysis with high performance liquid chromatography (HPLC) and electrochemical detection (ECD) for the measurement of the dynamics of norepinephrine (NE) in the olfactory bulbs of Sprague-Dawley rats following olfactory dysfunction induced by brain ischemia and its responses toward dexamethasone treatment. The method possesses a high spatial resolution and benefits from in vivo microdialysis and high selectivity and is thus capable of measuring NE in the olfactory bulb of rats. With this method, the basal level of NE in the olfactory bulb was evaluated to be ca. 235 ± 25 nM (n = 6). This level was found to increase by 260 ± 90% at a time point of 240 min after brain ischemia with bilateral ligation of both common carotid arteries. The increase was found to be suppressed upon the treatment of the animals with 0.2% dexamethasone in the olfactory bulb. These results suggest that NE is involved in the pathological process of ischemia-induced olfactory dysfunction and this information is useful to further understand the molecular events involved in olfactory dysfunction.


Assuntos
Dexametasona/uso terapêutico , Norepinefrina/metabolismo , Transtornos do Olfato/tratamento farmacológico , Bulbo Olfatório/fisiopatologia , Animais , Isquemia Encefálica/complicações , Cromatografia Líquida de Alta Pressão/métodos , Técnicas Eletroquímicas/métodos , Limite de Detecção , Masculino , Microdiálise/métodos , Norepinefrina/análise , Transtornos do Olfato/etiologia , Bulbo Olfatório/patologia , Ratos Sprague-Dawley
15.
Nano Lett ; 18(11): 6995-7003, 2018 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-30350638

RESUMO

Noncovalent interactions between single-stranded DNA (ssDNA) oligonucleotides and single wall carbon nanotubes (SWNTs) have provided a unique class of tunable chemistries for a variety of applications. However, mechanistic insight into both the photophysical and intermolecular phenomena underlying their utility is lacking, which results in obligate heuristic approaches for producing ssDNA-SWNT based technologies. In this work, we present an ultrasensitive "turn-on" nanosensor for neuromodulators dopamine and norepinephrine with strong relative change in fluorescence intensity (Δ F/ F0) of up to 3500%, a signal appropriate for in vivo neuroimaging, and uncover the photophysical principles and intermolecular interactions that govern the molecular recognition and fluorescence modulation of this nanosensor synthesized from the spontaneous self-assembly of (GT)6 ssDNA rings on SWNTs. The fluorescence modulation of the ssDNA-SWNT conjugate is shown to exhibit remarkable sensitivity to the ssDNA sequence chemistry, length, and surface density, providing a set of parameters with which to tune nanosensor dynamic range, analyte selectivity and strength of fluorescence turn-on. We employ classical and quantum mechanical molecular dynamics simulations to rationalize our experimental findings. Calculations show that (GT)6 ssDNA form ordered rings around (9,4) SWNTs, inducing periodic surface potentials that modulate exciton recombination lifetimes. Further evidence is presented to elucidate how dopamine analyte binding modulates SWNT fluorescence. We discuss the implications of our findings for SWNT-based molecular imaging applications.


Assuntos
Técnicas Biossensoriais/métodos , DNA de Cadeia Simples/química , Dopamina/análise , Fluorescência , Nanotubos de Carbono/química , Neurotransmissores/análise , Norepinefrina/análise , Oligonucleotídeos/química
16.
Biochem Biophys Res Commun ; 504(1): 103-108, 2018 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-30170732

RESUMO

AIM OF THE RESEARCH: Glutamate transporter-1 (GLT-1; also known as excitatory amino acid transporter 2) plays an important role in the maintenance of glutamate homeostasis in the synaptic cleft. Downregulation of GLT-1 in the spinal cord has been reported in chronic pain models, which suggests that GLT-1 is involved in the development of chronic pain. However, the mechanism by which GLT-1 is downregulated in the spinal cord is still unknown. We hypothesized that norepinephrine is involved in the regulation of GLT-1. The aim of this study was to investigate the effect of norepinephrine on GLT-1 expression in cultured astrocytes. METHODS: This study involved both in vivo and in vitro experiments. We first validated changes in GLT-1 mRNA expression in the spinal cord of rats with spared nerve injury (SNI) using real-time RT-PCR. Next, cultured primary astrocytes from the rat spinal cord were stimulated with norepinephrine, and GLT-1 mRNA was subsequently quantitated. RNB cells, an astrocytic cell line, were also stimulated with norepinephrine and other α-adrenoceptor agonists. RESULTS: SNI resulted in bilateral downregulation of GLT-1 in rat spinal cord. The in vitro study showed that norepinephrine and phenylephrine dose-dependently downregulated GLT-1 in primary astrocytes and RNB cells. Furthermore, the effect of norepinephrine was reversed by an α-adrenoceptor antagonist. CONCLUSION: Norepinephrine downregulates GLT-1 mRNA expression in astrocytes via the α1-adrenoceptor. Our results provide new insight into the mechanisms involved in downregulation of GLT-1 in the chronic pain models.


Assuntos
Astrócitos/metabolismo , Transportador 2 de Aminoácido Excitatório/metabolismo , Norepinefrina/farmacologia , Animais , Astrócitos/efeitos dos fármacos , Linhagem Celular , Células Cultivadas , Regulação para Baixo , Transportador 2 de Aminoácido Excitatório/genética , Masculino , Neuralgia/genética , Neuralgia/metabolismo , Norepinefrina/análise , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Medula Espinal/metabolismo , Corno Dorsal da Medula Espinal/química
17.
Endocr Pathol ; 29(4): 302-309, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30155766

RESUMO

In chromaffin cells, tyrosine hydroxylase (TH), aromatic L-amino acid decarboxylase (AADC), dopamine ß-hydroxylase (DBH), and phenylethanolamine N-methyltransferase (PNMT) are mainly involved in catecholamine synthesis. In this study, we evaluated the association between the status of catecholamine-synthesizing enzymes and histopathological features of pheochromocytoma and extraadrenal paraganglioma with special emphasis upon their postoperative clinical behavior. Immunohistochemical evaluation of TH, DBH, AADC, PNMT, Ki 67, and S-100 was performed in 29 pheochromocytoma and 10 extraadrenal paraganglioma and one lymph node harboring metastatic pheochromocytoma. Among these cases, metastasis was subsequently developed in three cases. Urinary normetanephrine (U-NM) levels were significantly higher in clinical metastatic cases than non-metastatic ones. Ki 67 labeling index was significantly higher in both clinical metastatic cases and the Adrenal Gland Scaled Score (PASS) score of ≧ 4 cases than PASS < 4 cases, although this score was originally used in pheochromocytoma. H-score of AADC and DBH were significantly lower in PASS ≧ 4 cases than those with < 4 cases, and in the cases associated with intratumoral necrosis (n = 4), the presence of spindle shaped tumor cells (n = 4), and large nests of cells or diffuse growth (n = 5). Lower status of intratumoral AADC could be related to poor differentiation of tumor cells in both catecholamine production and morphology and could be related to aggressive biological behavior of both pheochromocytoma and extraadrenal paraganglioma.


Assuntos
Neoplasias das Glândulas Suprarrenais/enzimologia , Catecolaminas/biossíntese , Paraganglioma Extrassuprarrenal/enzimologia , Feocromocitoma/enzimologia , Neoplasias das Glândulas Suprarrenais/patologia , Adulto , Descarboxilases de Aminoácido-L-Aromático/análise , Descarboxilases de Aminoácido-L-Aromático/metabolismo , Doenças do Sistema Nervoso Autônomo/metabolismo , Dopamina beta-Hidroxilase/análise , Dopamina beta-Hidroxilase/deficiência , Dopamina beta-Hidroxilase/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Norepinefrina/análise , Norepinefrina/deficiência , Norepinefrina/metabolismo , Paraganglioma Extrassuprarrenal/patologia , Feniletanolamina N-Metiltransferase/análise , Feniletanolamina N-Metiltransferase/metabolismo , Feocromocitoma/patologia , Tirosina 3-Mono-Oxigenase/análise , Tirosina 3-Mono-Oxigenase/metabolismo
18.
Biosens Bioelectron ; 114: 78-88, 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-29783145

RESUMO

The ability to view biological events in real time has contributed significantly to research in the life sciences. While video capture of real time changes in anatomical relationships is important, it is equally important to visualize real time changes in the chemical communications that drive cell behaviors. This paper describes an electrochemical imaging system capable of capturing changes in chemical gradients in live tissue slices. The system consists of a CMOS microchip with 8192 configurable Pt surface electrodes, on-chip potentiostat, on-chip control logic, and a microfluidic device designed to interface with the CMOS chip to support ex vivo tissue experimentation. All data processing and visualization methods, sensor calibrations, microfluidics fabrication, and tissue preparation and handling procedures are described. Using norepinephrine as a target analyte for proof of concept, the system is capable of differentiating concentrations of norepinephrine as low as 8 µM and up to 1024 µM with a linear response and a spatial resolution of 25.5 µm × 30.4 µm. Electrochemical imaging was tested using murine adrenal tissue as a biological model and successfully showed caffeine-stimulated release of catecholamines from live slices of adrenal tissue with temporal sensitivity. This system successfully demonstrates the use of a high-density microelectrode array for electrochemical analysis with high spatiotemporal resolution to gather chemical gradient information in parallel with optical microscopy recordings.


Assuntos
Técnicas Biossensoriais/instrumentação , Catecolaminas/análise , Técnicas Eletroquímicas/instrumentação , Norepinefrina/análise , Glândulas Suprarrenais/metabolismo , Animais , Cafeína/farmacologia , Catecolaminas/metabolismo , Desenho de Equipamento , Feminino , Dispositivos Lab-On-A-Chip , Limite de Detecção , Masculino , Camundongos , Microeletrodos , Norepinefrina/metabolismo , Oxirredução , Estudo de Prova de Conceito
19.
BMC Res Notes ; 11(1): 248, 2018 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-29673396

RESUMO

OBJECTIVE: Norepinephrine (NE), a sympathetic neurotransmitter, is often measured in plasma as an index of sympathetic activity. To better understand NE dynamics, it is important to measure its principal metabolite, 3,4-dihydroxyphenylglycol (DHPG), concurrently. Our aim was to present a method, developed in the course of a translational research study, to measure NE and DHPG in human plasma using high performance liquid chromatography with electrochemical detection (HPLC-ED). RESULTS: After pre-purifying plasma samples by alumina extraction, we used HPLC-ED to separate and quantify NE and DHPG. In order to remove uric acid, which co-eluted with DHPG, a sodium bicarbonate wash was added to the alumina extraction procedure, and we oxidized the column eluates followed by reduction because catechols are reversibly oxidized whereas uric acid is irreversibly oxidized. Average recoveries of plasma NE and DHPG were 35.3 ± 1.0% and 16.3 ± 1.1%, respectively, and there was no detectable uric acid. Our estimated detection limits for NE and DHPG were approximately 85 pg/mL (0.5 pmol/mL) and 165 pg/mL (0.9 pmol/mL), respectively. The measurement of NE and DHPG in human plasma has wide applicability; thus, we describe a method to quantify plasma NE and DHPG in a laboratory setting as a useful tool for translational and clinical research.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Técnicas Eletroquímicas/métodos , Metoxi-Hidroxifenilglicol/análogos & derivados , Norepinefrina/análise , Norepinefrina/sangue , Sistema Nervoso Simpático/metabolismo , Pesquisa Médica Translacional/métodos , Insuficiência Cardíaca/sangue , Humanos , Metoxi-Hidroxifenilglicol/análise , Metoxi-Hidroxifenilglicol/sangue
20.
Biochem Biophys Res Commun ; 501(1): 80-84, 2018 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-29689267

RESUMO

Synchronous spawning as mass reproduction is well known to occur in many hermatypic corals, which is one of the mysterious life birth events. However, its contributing mechanism has not yet been clarified. This study placed focus on elucidating a neurotransmitter as endocrine signals that contribute to the synchronous spawning. First, the determination method of the neurotransmitters in coral was established by LC/MS in the selective ion mode together with a solid phase extraction method. As a result, the similar contents of the neurotransmitters for dopamine (DA), adrenaline (AD) and noradrenaline (NR) were detected in both the hermatypic corals of Acropora intermedia and Acropora digitifera. More interestingly, these neurotransmitters increased through the reproductive event during the synchronous spawning of A. intermedia, particularly, remarkable changes in the NR and DA were observed. In addition, hydrogen peroxide is known as the spawning stimulant and the metabolic by-product of the neurotransmitters, which was exposed to A. digitifera, then the neurotransmitters increased as well as those of the synchronization of spawning. All of the results suggested that the neurotransmitters contribute to the synchronous spawning in the hermatypic corals.


Assuntos
Antozoários/fisiologia , Hormônios de Invertebrado/fisiologia , Neurotransmissores/fisiologia , Animais , Cromatografia Líquida , Dopamina/análise , Dopamina/fisiologia , Epinefrina/análise , Epinefrina/fisiologia , Hormônios de Invertebrado/análise , Neurotransmissores/análise , Norepinefrina/análise , Norepinefrina/fisiologia , Reprodução/fisiologia , Extração em Fase Sólida , Espectrometria de Massas por Ionização por Electrospray
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