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1.
ArXiv ; 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37547654

RESUMO

Photoacoustic computed tomography (PACT) is a proven technology for imaging hemodynamics in deep brain of small animal models. PACT is inherently compatible with ultrasound (US) imaging, providing complementary contrast mechanisms. While PACT can quantify the brain's oxygen saturation of hemoglobin (sO2), US imaging can probe the blood flow based on the Doppler effect. Further, by tracking gas-filled microbubbles, ultrasound localization microscopy (ULM) can map the blood flow velocity with sub-diffraction spatial resolution. In this work, we present a 3D deep-brain imaging system that seamlessly integrates PACT and ULM into a single device, 3D-PAULM. Using a low ultrasound frequency of 4 MHz, 3D-PAULM is capable of imaging the whole-brain hemodynamic functions with intact scalp and skull in a totally non-invasive manner. Using 3D-PAULM, we studied the mouse brain functions with ischemic stroke. Multi-spectral PACT, US B-mode imaging, microbubble-enhanced power Doppler (PD), and ULM were performed on the same mouse brain with intrinsic image co-registration. From the multi-modality measurements, we future quantified blood perfusion, sO2, vessel density, and flow velocity of the mouse brain, showing stroke-induced ischemia, hypoxia, and reduced blood flow. We expect that 3D-PAULM can find broad applications in studying deep brain functions on small animal models.

2.
Math Biosci ; 364: 109056, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37549786

RESUMO

Pulmonary hypertension (PH), defined by a mean pulmonary arterial blood pressure above 20 mmHg in the main pulmonary artery, is a cardiovascular disease impacting the pulmonary vasculature. PH is accompanied by chronic vascular remodeling, wherein vessels become stiffer, large vessels dilate, and smaller vessels constrict. Some types of PH, including hypoxia-induced PH (HPH), also lead to microvascular rarefaction. This study analyzes the change in pulmonary arterial morphometry in the presence of HPH using novel methods from topological data analysis (TDA). We employ persistent homology to quantify arterial morphometry for control and HPH mice characterizing normalized arterial trees extracted from micro-computed tomography (micro-CT) images. We normalize generated trees using three pruning algorithms before comparing the topology of control and HPH trees. This proof-of-concept study shows that the pruning method affects the spatial tree statistics and complexity. We find that HPH trees are stiffer than control trees but have more branches and a higher depth. Relative directional complexities are lower in HPH animals in the right, ventral, and posterior directions. For the radius pruned trees, this difference is more significant at lower perfusion pressures enabling analysis of remodeling of larger vessels. At higher pressures, the arterial networks include more distal vessels. Results show that the right, ventral, and posterior relative directional complexities increase in HPH trees, indicating the remodeling of distal vessels in these directions. Strahler order pruning enables us to generate trees of comparable size, and results, at all pressure, show that HPH trees have lower complexity than the control trees. Our analysis is based on data from 6 animals (3 control and 3 HPH mice), and even though our analysis is performed in a small dataset, this study provides a framework and proof-of-concept for analyzing properties of biological trees using tools from Topological Data Analysis (TDA). Findings derived from this study bring us a step closer to extracting relevant information for quantifying remodeling in HPH.


Assuntos
Hipertensão Pulmonar , Artéria Pulmonar , Camundongos , Animais , Artéria Pulmonar/diagnóstico por imagem , Hipertensão Pulmonar/diagnóstico por imagem , Hipertensão Pulmonar/complicações , Microtomografia por Raio-X , Hipóxia/complicações , Remodelação Vascular
3.
Inquiry ; 59: 469580221097427, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35514077

RESUMO

Distance counselling holds immense potential for improving access to trauma supports for survivors of sexual violence (SV), and particularly for under-served groups who disproportionately experience violence and myriad barriers to accessing in-person supports. And yet, the evidence-base for the practice and delivery of distance counselling remains under-developed. In the context of COVID-19, where telehealth applications have undergone a rapid uptake, we undertook a scoping review of existing evidence of therapeutic and organizational practices related to the real-time (synchronous) delivery of distance counselling to survivors of SV. We based our scoping review methods on Arksey and O'Malley framework and in accordance with the guidance on scoping reviews from the Joanna Briggs Institute (JBI) and PRISMA reporting guidelines for scoping reviews. A comprehensive search of MEDLINE, Embase, PsycINFO, CINAHL, Web of Science, and Sociological Abstracts was undertaken in October 2020, and again in March 2022. Searching, reviewing, appraisal, and data extraction was undertaken by two reviewers. In total, 1094 records were identified that resulted in 20 studies included. Descriptions, findings, and recommendations were gleaned and synthesized into potential practices using inductive thematic analysis. While many studies have an appreciative orientation to distance counselling, these benefits tend to be framed as non-universal, and conditional on survivor safety, flexibility, anonymity, survivor choice, strong and inclusive technology, and a supported workforce.Despite the limited evidence-base, we present several clusters of findings that, taken together, can be used to support current COVID-19 distance counselling initiatives with survivors, as well as guide the future development of best practices.


Assuntos
COVID-19 , Aconselhamento a Distância , Delitos Sexuais , Telemedicina , Humanos , Sobreviventes
5.
BMJ Open ; 9(9): e029258, 2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533946

RESUMO

OBJECTIVES: Treatment burden is the workload of healthcare for people with long-term conditions (LTC) and its impact on well-being. A method of measurement is required to identify those experiencing high burden and to measure intervention efficacy. Our aim was to identify, examine and appraise validated patient-reported measures (PRMs) of treatment burden in stroke. Here, stroke serves as an exemplar LTC of older adults. DESIGN: A systematic review of published studies that describe the development and validation of PRMs measuring treatment burden in stroke survivors. DATA SOURCES: We searched MEDLINE, Embase, CINAHL and PsycINFO electronic databases. ELIGIBILITY CRITERIA: Studies published between January 2000 and 12 April 2019 inclusive, in English language. No restrictions were set based on clinical setting or geographical location. DATA EXTRACTION AND SYNTHESIS: Screening, data extraction and quality appraisal were conducted by two independent reviewers. Content of the PRMs was compared with a published taxonomy of treatment burden. Quality appraisal was conducted using International Society for Quality of Life Research standards. RESULTS: From 3993 articles, 6 relevant PRMs were identified: 3 were stroke specific: The Satisfaction with Stroke Care questionnaire; The Stroke Patient-Reported Outcome Measure and The Barriers to Physical Activity after Stroke scale. Three were generic but validated in stroke: The WHO Quality of Life-100; The Patient's Questionnaire on Participation in Discharge Planning and The Chao Perception of Continuity scale. None comprehensively measured treatment burden. Examples of omitted burdens included developing coping strategies, managing finances and returning to driving. The most notable issue regarding quality appraisal was that three PRMs lacked any underpinning qualitative research relevant to the sample. CONCLUSION: There is a need to develop a comprehensive PRM of treatment burden for use in stroke, with potential for use in other older populations.


Assuntos
Medidas de Resultados Relatados pelo Paciente , Acidente Vascular Cerebral/terapia , Humanos , Carga de Trabalho
6.
Sci Rep ; 7(1): 291, 2017 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-28331198

RESUMO

Photopharmacology describes the use of light to precisely deliver drug activity in space and time. Such approaches promise to improve drug specificity by reducing off-target effects. As a proof-of-concept, we have subjected the fourth generation photoswitchable sulfonylurea JB253 to comprehensive toxicology assessment, including mutagenicity and maximum/repeated tolerated dose studies, as well as in vivo testing in rodents. Here, we show that JB253 is well-tolerated with minimal mutagenicity and can be used to optically-control glucose homeostasis in anesthetized mice following delivery of blue light to the pancreas. These studies provide the first demonstration that photopharmacology may one day be applicable to the light-guided treatment of type 2 diabetes and other metabolic disease states in vivo in humans.


Assuntos
Diabetes Mellitus/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Fármacos Fotossensibilizantes/administração & dosagem , Compostos de Sulfonilureia/administração & dosagem , Animais , Glicemia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Homeostase , Hipoglicemiantes/efeitos adversos , Camundongos , Fármacos Fotossensibilizantes/efeitos adversos , Compostos de Sulfonilureia/efeitos adversos , Resultado do Tratamento
7.
Cell Metab ; 24(3): 389-401, 2016 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-27452146

RESUMO

The arrangement of ß cells within islets of Langerhans is critical for insulin release through the generation of rhythmic activity. A privileged role for individual ß cells in orchestrating these responses has long been suspected, but not directly demonstrated. We show here that the ß cell population in situ is operationally heterogeneous. Mapping of islet functional architecture revealed the presence of hub cells with pacemaker properties, which remain stable over recording periods of 2 to 3 hr. Using a dual optogenetic/photopharmacological strategy, silencing of hubs abolished coordinated islet responses to glucose, whereas specific stimulation restored communication patterns. Hubs were metabolically adapted and targeted by both pro-inflammatory and glucolipotoxic insults to induce widespread ß cell dysfunction. Thus, the islet is wired by hubs, whose failure may contribute to type 2 diabetes mellitus.


Assuntos
Glucose/farmacologia , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Animais , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/efeitos da radiação , Diferenciação Celular/efeitos dos fármacos , Sistemas Computacionais , Diabetes Mellitus/patologia , Homeostase/efeitos dos fármacos , Homeostase/efeitos da radiação , Humanos , Insulina/metabolismo , Secreção de Insulina , Luz , Lipídeos/toxicidade , Metaboloma/efeitos dos fármacos , Metabolômica , Camundongos , Fenômenos Ópticos , Fenótipo , Especificidade da Espécie
8.
Angew Chem Int Ed Engl ; 55(19): 5865-8, 2016 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-27059784

RESUMO

Allosteric regulation promises to open up new therapeutic avenues by increasing drug specificity at G-protein-coupled receptors (GPCRs). However, drug discovery efforts are at present hampered by an inability to precisely control the allosteric site. Herein, we describe the design, synthesis, and testing of PhotoETP, a light-activated positive allosteric modulator of the glucagon-like peptide-1 receptor (GLP-1R), a class B GPCR involved in the maintenance of glucose homeostasis in humans. PhotoETP potentiates Ca(2+) , cAMP, and insulin responses to glucagon-like peptide-1 and its metabolites following illumination of cells with blue light. PhotoETP thus provides a blueprint for the production of small-molecule class B GPCR allosteric photoswitches, and may represent a useful tool for understanding positive cooperativity at the GLP-1R.


Assuntos
Compostos de Anilina/farmacologia , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Regulação Alostérica/efeitos da radiação , Compostos de Anilina/síntese química , Compostos de Anilina/química , Animais , Compostos Azo/química , Células CHO , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/genética , Humanos , Insulina/metabolismo , Isomerismo , Luz , Pirimidinas/química , Pirimidinas/farmacologia , Raios Ultravioleta
10.
Angew Chem Int Ed Engl ; 54(51): 15565-9, 2015 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-26585495

RESUMO

Incretin mimetics are set to become a mainstay of type 2 diabetes treatment. By acting on the pancreas and brain, they potentiate insulin secretion and induce weight loss to preserve normoglycemia. Despite this, incretin therapy has been associated with off-target effects, including nausea and gastrointestinal disturbance. A novel photoswitchable incretin mimetic based upon the specific glucagon-like peptide-1 receptor (GLP-1R) agonist liraglutide was designed, synthesized, and tested. This peptidic compound, termed LirAzo, possesses an azobenzene photoresponsive element, affording isomer-biased GLP-1R signaling as a result of differential activation of second messenger pathways in response to light. While the trans isomer primarily engages calcium influx, the cis isomer favors cAMP generation. LirAzo thus allows optical control of insulin secretion and cell survival.


Assuntos
Incretinas/química , Insulina/metabolismo , Liraglutida/farmacologia , Sequência de Aminoácidos , Animais , Células CHO , Linhagem Celular Transformada , Cricetinae , Cricetulus , Diabetes Mellitus Tipo 2/tratamento farmacológico , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Secreção de Insulina , Liraglutida/química , Liraglutida/uso terapêutico , Camundongos , Mimetismo Molecular , Dados de Sequência Molecular , Transdução de Sinais
11.
Australas Psychiatry ; 23(5): 566-70, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26224698

RESUMO

OBJECTIVE: A comparison of the timing, rates and characteristics of electroconvulsive therapy use between urban and rural populations. METHOD: The medical records of patients who received an acute course of electroconvulsive therapy at two rural and two urban psychiatric hospitals in New South Wales (NSW), Australia, in 2010 were reviewed retrospectively. Main outcome measures were the time from symptom onset, diagnosis and admission to commencing electroconvulsive therapy. Rates of use of electroconvulsive therapy were also compared between rural and urban hospitals using NSW statewide data. RESULTS: There was a significant delay in the time it took for rural patients to receive electroconvulsive therapy compared with urban patients when measured both from the time of symptom onset and from when they received a diagnosis. There were corresponding delays in the time taken for rural patients to be admitted to hospital compared with urban patients. There was no difference in the time it took to commence electroconvulsive therapy once a patient was admitted to hospital. NSW statewide urban-rural comparisons showed rates of electroconvulsive therapy treatment were significantly higher in urban hospitals. CONCLUSIONS: Patients in rural areas receive electroconvulsive therapy later in their acute illness due to delays in being admitted to hospital. The rate of use of electroconvulsive therapy also differs geographically.


Assuntos
Eletroconvulsoterapia/estatística & dados numéricos , Disparidades em Assistência à Saúde/estatística & dados numéricos , Hospitais Psiquiátricos/estatística & dados numéricos , População Rural/estatística & dados numéricos , População Urbana/estatística & dados numéricos , Austrália , Humanos
12.
Dev Neurosci ; 36(3-4): 220-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24821576

RESUMO

There is a significant inflection in risk taking and criminal behavior during adolescence, but the basis for this increase remains largely unknown. An increased sensitivity to rewards has been suggested to explain these behaviors, yet juvenile offences often occur in emotionally charged situations of negative valence. How behavior is altered by changes in negative emotional processes during adolescence has received less attention than changes in positive emotional processes. The current study uses a measure of impulsivity in combination with cues that signal threat or safety to assess developmental changes in emotional responses to threat cues. We show that adolescents, especially males, impulsively react to threat cues relative to neutral ones more than adults or children, even when instructed not to respond. This adolescent-specific behavioral pattern is paralleled by enhanced activity in limbic cortical regions implicated in the detection and assignment of emotional value to inputs and in the subsequent regulation of responses to them when successfully suppressing impulsive responses to threat cues. In contrast, prefrontal control regions implicated in detecting and resolving competing responses show an adolescent-emergent pattern (i.e. greater activity in adolescents and adults relative to children) during successful suppression of a response regardless of emotion. Our findings suggest that adolescence is a period of heightened sensitivity to social and emotional cues that results in diminished regulation of behavior in their presence.


Assuntos
Comportamento do Adolescente/fisiologia , Comportamento Impulsivo , Adolescente , Adulto , Criança , Sinais (Psicologia) , Medo , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Recompensa , Assunção de Riscos , Caracteres Sexuais , Adulto Jovem
13.
Mol Endocrinol ; 28(6): 860-71, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24766140

RESUMO

Incretins such as glucagon-like peptide 1 (GLP-1) are released from the gut and potentiate insulin release in a glucose-dependent manner. Although this action is generally believed to hinge on cAMP and protein kinase A signaling, up-regulated beta cell intermediary metabolism may also play a role in incretin-stimulated insulin secretion. By employing recombinant probes to image ATP dynamically in situ within intact mouse and human islets, we sought to clarify the role of GLP-1-modulated energetics in beta cell function. Using these techniques, we show that GLP-1 engages a metabolically coupled subnetwork of beta cells to increase cytosolic ATP levels, an action independent of prevailing energy status. We further demonstrate that the effects of GLP-1 are accompanied by alterations in the mitochondrial inner membrane potential and, at elevated glucose concentration, depend upon GLP-1 receptor-directed calcium influx through voltage-dependent calcium channels. Lastly, and highlighting critical species differences, beta cells within mouse but not human islets respond coordinately to incretin stimulation. Together, these findings suggest that GLP-1 alters beta cell intermediary metabolism to influence ATP dynamics in a species-specific manner, and this may contribute to divergent regulation of the incretin-axis in rodents and man.


Assuntos
Peptídeo 1 Semelhante ao Glucagon/fisiologia , Incretinas/fisiologia , Células Secretoras de Insulina/metabolismo , Trifosfato de Adenosina/metabolismo , Adulto , Animais , Sinalização do Cálcio , Metabolismo Energético , Receptor do Peptídeo Semelhante ao Glucagon 1 , Glucose/metabolismo , Humanos , Potencial da Membrana Mitocondrial , Camundongos , Pessoa de Meia-Idade , Receptores de Glucagon/metabolismo , Especificidade da Espécie , Técnicas de Cultura de Tecidos
14.
Gen Comp Endocrinol ; 188: 60-6, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23557645

RESUMO

The capa peptide family, originally identified in the tobacco hawk moth, Manduca sexta, is now known to be present in many insect families, with increasing publications on capa neuropeptides each year. The physiological actions of capa peptides vary depending on the insect species but capa peptides have key myomodulatory and osmoregulatory functions, depending on insect lifestyle, and life stage. Capa peptide signaling is thus critical for fluid homeostasis and survival, making study of this neuropeptide family attractive for novel routes for insect control. In Dipteran species, including the genetically tractable Drosophila melanogaster, capa peptide action is diuretic; via elevation of nitric oxide, cGMP and calcium in the principal cells of the Malpighian tubules. The identification of the capa receptor (capaR) in several insect species has shown this to be a canonical GPCR. In D. melanogaster, ligand-activated capaR activity occurs in a dose-dependent manner between 10(-6) and 10(-12)M. Lower concentrations of capa peptide do not activate capaR, either in adult or larval Malpighian tubules. Use of transgenic flies in which capaR is knocked-down in only Malpighian tubule principal cells demonstrates that capaR modulates tubule fluid secretion rates and in doing so, sets the organismal response to desiccation. Thus, capa regulates a desiccation-responsive pathway in D. melanogaster, linking its role in osmoregulation and fluid homeostasis to environmental response and survival. The conservation of capa action between some Dipteran species suggests that capa's role in desiccation tolerance may not be confined to D. melanogaster.


Assuntos
Proteínas de Drosophila/metabolismo , Neuropeptídeos/metabolismo , Animais , Cálcio/metabolismo , GMP Cíclico/metabolismo , Drosophila melanogaster , Túbulos de Malpighi/metabolismo , Transdução de Sinais/fisiologia
15.
PLoS One ; 7(6): e38854, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22723896

RESUMO

High-pain expectancy increases pain and pain-related brain activity, creating a cycle of psychologically maintained pain. Though these effects are robust, little is known about how expectancy works and what psychological processes either support or mitigate its effects. To address this, we independently manipulated pain expectancy and "top-down" attention to the body, and examined their effects on both a performance-based measure of body-focus and heat-induced pain. Multi-level mediation analyses showed that high-pain expectancy substantially increased pain, replicating previous work. However, attention to the body reduced pain, partially suppressing the effects of expectancy. Furthermore, increased body-focus had larger pain-reducing effects when pain expectancy was high, suggesting that attempts to focus on external distractors are counterproductive in this situation. Overall, the results show that attention to the body cannot explain pain-enhancing expectancy effects, and that focusing on sensory/discriminative aspects of pain might be a useful pain-regulation strategy when severe pain is expected.


Assuntos
Atenção , Dor/psicologia , Adolescente , Adulto , Encéfalo/fisiologia , Feminino , Temperatura Alta/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Adulto Jovem
16.
J Pediatr Psychol ; 31(6): 529-39, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16034003

RESUMO

OBJECTIVE: To examine the supervision that young children routinely receive when awake and at home with a parent. METHODS: Mothers were trained to complete continuous recordings about supervision of their young child (2-5 years) when at home on each of 10 randomly selected days within a 3-week period. RESULTS: Children were supervised more often than unsupervised but were completely out of view of supervisors about 20% of their awake time, and supervision was poorer when out of view of supervisors. Older children (4-5 years) were unsupervised (8% of awake time) more often than younger children (2-3 years; 1%), were more often out of view of supervisors than younger children, and received poorer supervision than younger children when out of view of supervisors. Few sex differences were found. CONCLUSIONS: These data provide insights into the nature and scope of supervision that young children routinely experience when at home. Implications of these findings for identifying patterns of supervision that elevate children's risk of injury are discussed.


Assuntos
Atitude , Cuidadores , Intenção , Relações Mãe-Filho , Meio Social , Ferimentos e Lesões/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Prevalência
17.
J Pediatr Psychol ; 31(6): 540-51, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16135850

RESUMO

OBJECTIVE: To identify child and parent attributes that relate to caregiver supervision and examine how these factors influence child-injury risk. METHODS: Mothers completed diary records about supervision of their young child (2-5 years) when at home. Standardized questionnaires provided information about child attributes, maternal attributes, and children's history of injuries. RESULTS: Correlations revealed that child attributes and parent attributes related both to actual maternal supervision and child-injury scores. Regression analyses to predict injury scores revealed child-temperament factors alone predicted all levels of severity (minor, moderately severe, and medically attended), but parent supervision also contributed to predict medically attended injuries. CONCLUSIONS: Both child and parent factors influenced caregiver's supervision of young children at home and related to child-injury risk. For medically attended injuries, child attributes and parent supervision both predicted risk, whereas for less serious injuries, child factors alone determined risk.


Assuntos
Atitude , Cuidadores , Comportamento Infantil/psicologia , Intenção , Relações Mãe-Filho , Pais/psicologia , Ferimentos e Lesões/epidemiologia , Pré-Escolar , Feminino , Humanos , Masculino , Psicometria , Fatores de Risco , Temperamento , Ferimentos e Lesões/prevenção & controle
18.
Pain ; 105(1-2): 205-13, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14499437

RESUMO

Transcutaneous electrical nerve stimulation (TENS) is a form of non-pharmacological treatment for pain. Involvement of descending inhibitory systems is implicated in TENS-induced analgesia. In the present study, the roles of spinal 5-HT and alpha(2)-adrenoceptors in TENS analgesia were investigated in rats. Hyperalgesia was induced by inflaming the knee joint with 3% kaolin-carrageenan mixture and assessed by measuring paw withdrawal latency (PWL) to heat before and 4 h after injection. The (1). alpha(2)-adrenergic antagonist yohimbine (30 microg), (2). 5-HT antagonist methysergide (5-HT(1). and 5-HT(2). 30 microg), one of the 5-HT receptor subtype antagonists, (3). NAN-190 (5-HT(1A), 15 microg), (4). ketanserin (5-HT(2A), 30 microg), (5). MDL-72222 (5-HT(3), 12 microg), or (6). vehicle was administered intrathecally prior to TENS treatment. Low (4 Hz) or high (100 Hz) frequency TENS at sensory intensity was then applied to the inflamed knee for 20 min and PWL was determined. Selectivity of the antagonists used was confirmed using respective agonists administered intrathecally. Yohimbine had no effect on the antihyperalgesia produced by low or high frequency TENS. Methysergide and MDL-72222 prevented the antihyperalgesia produced by low, but not high, frequency TENS. Ketanserin attenuated the antihyperalgesic effects of low frequency TENS whereas NAN-190 had no effect. The results from the present study show that spinal 5-HT receptors mediate low, but not high, frequency TENS-induced antihyperalgesia through activation of 5-HT(2A) and 5-HT(3) receptors in rats. Furthermore, spinal noradrenergic receptors are not involved in either low or high frequency TENS antihyperalgesia.


Assuntos
Hiperalgesia/fisiopatologia , Receptores de Serotonina/metabolismo , Medula Espinal/metabolismo , Estimulação Elétrica Nervosa Transcutânea , Antagonistas Adrenérgicos alfa/administração & dosagem , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Carragenina , Hiperalgesia/induzido quimicamente , Hiperalgesia/metabolismo , Injeções Espinhais , Caulim , Masculino , Metisergida/administração & dosagem , Metisergida/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina , Receptores 5-HT3 de Serotonina , Antagonistas da Serotonina/administração & dosagem , Antagonistas da Serotonina/farmacologia , Ioimbina/administração & dosagem , Ioimbina/farmacologia
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